Library Catalogs

Published library catalogs and OPACs are essential sources for locating copies, identifying unique items, building a preliminary bibliography, and conducting subject searches. Researchers who have only rudimentary skill in searching an OPAC should read the chapter on using library catalogs (pp. 9–26) in Baker and Huling, A Research Guide for Undergraduate Students (B80).

Bibliographies and Guides


Downs, Robert B. American Library Resources: A Bibliographical Guide. Chicago: Amer. Lib. Assn., 1951. 428 pp. Supplement, 1950–1961. 1962. 226 pp. Supplement, 1961–1970. 1972. 244 pp. Supplement, 1971–1980. 1981. 209 pp. American Library Resources: Cumulative Index, 1870–1970. Comp. Clara D. Keller. 1981. 89 pp. Z1002.D6 016.016.

———. British and Irish Library Resources: A Bibliographical Guide. London: Mansell, 1981. 427 pp. Z791.A1 D68 016.0252′07.

The works list printed catalogs, guides to libraries, union lists, descriptions of collections, calendars, indexes, surveys of holdings, and exhibition catalogs, along with some library reports, miscellaneous bibliographies, and unpublished works. Users must remember that the Library Resources volumes are guides to published materials and not to collections themselves. Entries are listed alphabetically by library or author within classified subject divisions, including ones for general works (with sections for general library catalogs, manuscripts, rare books, and printing history), social sciences (including folklore), linguistics, literature (organized by national literatures, with subsections in the American volumes for general works, genres, and individual authors), and biography and genealogy. The British volume is more extensively and precisely classified and includes a division for individuals (predominantly literary authors), but it is far less thorough than the American volumes. Some entries are accompanied by a brief description of content. Indexed in each American volume and the Cumulative Index by persons, subjects, and libraries; the British volume has two indexes: authors, compilers, and editors; subjects. Because of inadequate subject indexing, inconsistencies in classifying items, and a lack of cross-references, users must exercise considerable ingenuity to locate all works on a topic or library. Although incomplete in covering journal articles and general bibliographies that cite locations, the Library Resources volumes are valuable for identifying works that provide important access to special collections and describe unique items. They are especially strong in covering local publications that usually are not listed in the standard bibliographies and indexes given in section G, in American Book Publishing Record (Q4110), or in Books in Print (Q4225). Review: (British) R. J. Roberts, Notes and Queries ns 31.2 (1984): 252–53.


Nelson, Bonnie R. A Guide to Published Library Catalogs. Metuchen: Scarecrow, 1982. 342 pp. Z710.N44 019.

A classified list of important general and specialized catalogs, the majority of which are multivolume works published since 1960 and representing the holdings of North American or Western European libraries. The approximately 429 entries are listed alphabetically by main entry in 33 divisions, with the following of most interest to literature researchers: general catalogs of major research libraries; manuscripts, rare books, and book arts; anthropology, American Indians, and folklore; American West; Continental languages and literatures; English and American literature; African and black studies; women’s studies; performing arts; and education and children’s books. A majority of the entries are accompanied by annotations that describe the organization of a catalog, its library classification and subject indexing system, and special features. Two indexes: subjects; libraries. Although Nelson omits some important catalogs published before 1960 and includes a few serial bibliographies that are not library catalogs, it is the best guide to published library catalogs (most of which have been superseded by publicly accessible OPACs).

See also

Secs. E: Libraries and Library Catalogs/Research Libraries/Guides to Collections and U: Literature-Related Topics and Sources/Bibliography and Textual Criticism/Guides to Scholarship/Serial Bibliographies.

ABELL (G340): Bibliography/Book Production, Selling, Collecting, Librarianship, the Newspaper (with variations in the title) in the volumes for 1934 through 1972; Bibliography/Booksellers’, Exhibition, and Sale Catalogues in the volumes for 1973 through 1984; and Bibliography/Collecting and the Library in the volumes for 1973 to the present.

MLAIB (G335): See the headings Collection Study and Collections in the index to post-1980 volumes and the online Thesaurus.

Taylor, Book Catalogues: Their Varieties and Uses (U5395).

Union Catalogs

Union catalogs are indispensable for identifying and locating copies of editions and translations of almost any book. Since entries reflect the cataloging practices of a variety of libraries, union catalogs generally include a number of ghosts and duplicate records for the same edition and must be used with care for verification of dates, titles, publishers, editions, or series. Although WorldCat (E225) is a more efficient, accessible, and (for recent books) comprehensive source than the National Union Catalogs (E235, E240, and E245), the following databases and printed catalogs are complementary research tools.



WorldCat. OCLC. OCLC: Online Computer Library Center, n.d. 8 Oct. 2012. <>. Updated daily. <>.

A database whose several million records for books, e-books, articles, journals, manuscripts, audio and video recordings, Internet sites, microforms, musical scores, maps, and software form the largest union catalog. Available through OCLC’s FirstSearch service, WorldCat can be searched at three levels:

  • Basic Search allows users to search keyword, author, title, ISBN, and date fields. Users should note that records are sorted by the number of libraries holding copies but that clicking Options sorts a maximum of 500 records by ascending or descending author, title, date, or number of libraries.

  • Advanced Search allows users to search a combination of fields: keyword, access method (e.g., URL), accession number, author, language, type of material, notes, publisher, place of publication, ISBN, ISSN, subject, and title. For each of these fields, users can browse an index list. Searches can be limited by date, language, number of libraries holding a work, type of document, audience, content (e.g., fiction, musical score), format (e.g., manuscript, LP recording), and documents held by a particular library. Records can be sorted by number of libraries holding copies, relevance, date, or accession number (essential for users who run the same search at intervals and want to determine what has been newly added to the database; the maximum number of records returned is 1,000). The default sort is number of libraries (usually the worst choice for a search that returns a large number of records). Users who set up an account (click My Account) can both save searches and change sort options permanently for a session; the Options link and the Sort button also allow sorting up to 500 records by ascending or descending author, title, date, or number of libraries.

  • Expert Search offers command-line searching of all records fields. Searches can be limited and records sorted the same as in Advanced Search.

Except for ampersands and hyphens, users must omit diacritics, punctuation marks, special characters, and symbols in search terms.

WorldCat records typically indicate if the subscribing institution has the document in its collection and provide a link for requesting the item through interlibrary loan. Previous searches can be rerun or combined. Records can be marked for printing, e-mailing, or downloading as a text file or into bibliographic software. Researchers should avoid the public version of WorldCat (, which offers much less sophisticated search interfaces. Searches of this do not identify all editions of a work in the WorldCat database.

Because of differences in cataloging practices by contributors, several records for the same edition may appear in a list. WorldCat also includes Cataloging-in-Publication records for books that were never actually published.

The extensive coverage (which for works published after 1956 generally surpasses that of NUC [E240] and NUC: Books [E245]), variety of access points, continual updating of information, interlibrary loan subsystem, and general ease of use make WorldCat more efficient to search than the NUCs. Given the magnitude and versatility of the database, no researcher can afford to ignore WorldCat, but users must remember that, despite the size of the database, coverage—especially of materials in languages other than English—becomes less thorough as one moves back in time. For a discussion of the overlap between WorldCat and NUC, Pre-56 (E235), see Beall, ““The Proportion of NUC, Pre-56 Titles Represented in OCLC WorldCat ”,” and DeZelar-Tiedman, ““The Proportion of NUC, Pre-56 Titles Represented in the RLIN and OCLC Databases Compared: A Follow-Up to the Beall/Kafadar Study”” (E235a).

WorldCat is an invaluable resource for literary and linguistic research: using it, a researcher can identify separately published works about a topic (and, increasingly, articles and parts of books, thanks to the inclusion of tables of contents in many recently added records), by or about an author, by a publisher, or in a series and—depending on the reported holdings of cooperating libraries—can discover what libraries hold copies and can expedite interlibrary loan by using WorldCat’s ordering subsystem.

In addition to WorldCat FirstSearch also allows access to other databases, including ArticleFirst (G400a), Chicano Database (Q3973a), ECO (an archive of about 5,000 full-text journals since 1995), ERIC (U5590), and PapersFirst (a bibliographic database of conference proceedings received by the British Library Document Supply Centre since 1993). Access is through a version of the WorldCat interface that is adapted to the record fields of the individual database.

See also

Copac (E250a).

Printed Catalogs


National Union Catalog, Pre-1956 Imprints (NUC, Pre-56). 754 vols. London: Mansell, 1968–81. Microfiche ed. Chicago: Amer. Lib. Assn., 1983. Z881.A1 U518 021.6′4.

An author catalog of reported holdings of the Library of Congress and about 1,000 other North American libraries. The majority of the 11,000,000 or so author entries are for printed works, although some manuscripts, theses, and dissertations are listed. Since entries reproduce catalog cards from many libraries, information ranges from detailed analytic descriptions to truncated records, but each entry identifies at least one library that owns an item. Users should keep the following points in mind:

  1. A work can be located only by author, title for an anonymous publication, or (sometimes) editor for an anthology or collection; WorldCat (E225), Library of Congress Shelflist (E260a), and LC Subject Catalog (E260a) provide subject access to some entries, and WorldCat and Cumulative Title Index to the Library of Congress Shelflist (E260a) offer title access.

  2. There are numerous errors and ghosts, particularly because a card that includes even a minor variation is frequently treated as representing an “edition.”

  3. Not all holdings of cooperating libraries are listed (e.g., works in non-Latin alphabets are included only if represented by a printed LC card).

  4. Listings for prolific major authors are subclassified.

  5. The supplement (vols. 686–754) corrects errors, provides the only adequate cross-references in the work, and records new titles, editions, and locations.

  6. Additional locations are recorded in National Union Catalog: Register of Additional Locations (1963–96, microform only after the volumes for 1979 [1980]).

Unfortunately, the widespread availability of WorldCat and the erroneous assumption that it includes everything in NUC, Pre-56 have prompted many libraries to move their set into storage or deaccession it. One study determined that 27.8% of the records in NUC, Pre-56 were not in WorldCat (Jeffrey Beall and Karen Kafadar, ““The Proportion of NUC, Pre-56 Titles Represented in OCLC WorldCat ”,” College and Research Libraries 66.5 [2005]: 431–35); see also the follow-up study by Christine DeZelar-Tiedman, ““The Proportion of NUC, Pre-56 Titles Represented in the RLIN and OCLC Databases Compared: A Follow-Up to the Beall/Kafadar Study”,” College and Research Libraries 69.5 (2008): 401–06.

For an account of the history and editing of the NUC, Pre-56, see David A. Smith, ““ The National Union Catalog, Pre-1956 Imprints ”,” Book Collector 31.4 (1982): 445–62. Continued by National Union Catalog (E240) and NUC: Books (E245).

Libraries unable to afford NUC, Pre-56 will probably have one or more of the following:

  • A Catalog of Books Represented by Library of Congress Printed Cards Issued to July 31, 1942. 167 vols. Ann Arbor: Edwards, 1942–46. Supplement: Cards Issued August 1, 1942–December 31, 1947. 42 vols. 1948.

  • Library of Congress and National Union Catalog Author Lists, 1942–1962: A Master Cumulation. 152 vols. Detroit: Gale, 1969–71. (This work incorporates the following catalogs.)

  • Library of Congress Author Catalog: A Cumulative List of Works Represented by Library of Congress Printed Cards, 1948–52. 24 vols. Ann Arbor: Edwards, 1953.

  • The National Union Catalog . . . 1953–57. 28 vols. Ann Arbor: Edwards, 1958.

For comprehensive searches involving several works or editions by an author, begin with NUC, Pre-56 and supplement its listings with WorldCat; for interlibrary loan requests or searches for a few specific works or editions, begin with WorldCat.


National Union Catalog: A Cumulative Author List Representing Library of Congress Printed Cards and Titles Reported by Other American Libraries (NUC). Washington: Lib. of Congress, 1958–83. 9/yr., with quarterly, annual, and quinquennial cumulations. Z881.A1 U372 018.1.

An author catalog that continues NUC, Pre-56 (E235) for works published after 1956. Since a work is not listed until a cooperating library prepares a catalog card, a book published outside the United States may not be entered until several years after its publication date. Additional locations are recorded in National Union Catalog: Register of Additional Locations (1963–96, microform only after the volumes for 1979 [1980]). Continued by NUC: Books (E245).

Cumulative Title Index to the Library of Congress Shelflist (E260a) and WorldCat (E225) offer title access to many works recorded in NUC; and LC Subject Catalog (E260a), WorldCat, and Library of Congress Shelflist (E260a) provide subject access to many listings. For author, title, or location searches, researchers will find WorldCat more efficient and generally more comprehensive than NUC.


NUC: Books. Washington: Lib. of Congress, 1983–2002. Microfiche. Published in five parts: Register, monthly; Name Index, Title Index, Series Index, Subject Index, quarterly, with annual and larger cumulations. NUC: US Books extracts records for books published in the United States.

A continuation of the National Union Catalog (E240). The Register—to which the other four parts are keyed—lists books by NUC number and is the only part that records full cataloging information. For locations other than the library that contributed the record, users must consult National Union Catalog: Register of Additional Locations (1963–96, microform only after the volumes for 1979 [1980]). The other parts are alphabetical indexes to the Register and, except for the Subject Index, print abbreviated entries. Although the four indexes remedy access problems that plague users of the earlier NUCs, they are time-consuming to search because of the necessity of consulting the numerically arranged Register and Register of Additional Locations for full cataloging and locations. Users would be better served if each index printed complete information and locations. Literary researchers will find WorldCat (E225) more efficient to use and generally more comprehensive than NUC: Books, especially beginning in 1990, when records were no longer included from WorldCat and from the now defunct RLG Union Catalog and Western Library Network.

See also

New Serial Titles (K640).

Serials in the British Library (K645).

Catalogs of National Libraries

Because of copyright deposit privileges and the magnitude and quality of their general collections, which transcend national boundaries, the major national libraries are among the great research centers. Their catalogs—many of which are available online—are essential complements to the union catalogs.


Explore the British Library. British Library. British Lib., n.d. 8 Oct. 2012. <>. Formerly British Library Integrated Catalogue.

A catalog of the majority of the printed books and periodicals held by the British Library that, for the most part, supersedes an unwieldy array of printed catalogs that were frequently difficult to search by anyone unfamiliar with the complex British Library cataloging rules. The main page of the Explore Web site lists materials not included; for manuscripts, see British Library Archives and Manuscripts Catalogue (F300). Simple Search allows keyword searches of the entire catalog, the holdings of the Newspaper Library, or material held in Remote Supply. Advanced Search allows users to limit searches by field (author, title, subject, description, place-name, map scale, abstract, and date), by type of material, and by the options in Simple Search. Results can be sorted by author (ascending), title (ascending), relevance, or date (ascending or descending). Depending on records returned, results can be refined in a varity of ways (e.g., type of material, subject, publication date, language, and publisher). Records can be marked for transfer to My Workspace, where they can be printed, e-mailed, or downloaded to bibliographic management software. British Library reader pass holders can save results, searches, and alerts to an account and request delivery of documents. Users should note that Explore the British Library is still a work in progress.

Those interested in the origin and evolution of the printed General Catalogue of Printed Books and its bewildering cataloging rules should consult A. H. Chaplin, GK: 150 Years of the General Catalogue of Printed Books in the British Museum (Aldershot: Scolar, 1987; 177 pp.). Researchers using specialized collections should consult the Help for Researchers page at the British Library Web site (

Because of the British Library’s extensive holdings, Explore the British Library is an invaluable source for identifying works by and about authors and allows readers to request copies in advance. Anyone not holding a current reader pass must read Registering for a Reader Pass (click on Reader Registration).

Holdings of the British Library can also be searched through Copac (, a union catalog of libraries in the United Kingdom (for a list of contributing libraries, click About/Libraries).


Catalogues. Bibliothèque Nationale de France. Bibliothèque Nationale de France, 2013. 22 Aug. 2013. <>. Updated weekly. The online catalogs of the Bibliothèque Nationale de France (BnF) relieve researchers from having to consult a bewildering array of printed catalogs (listed in part at the library’s Web site).

  • BnF catalogue général includes books, modern manuscripts, periodicals, and some other materials.

  • BnF archives et manuscrits includes manuscripts and other specialized collections.

The catalogs of the Bibliothèque Nationale de France, whose extensive collections of French publications (including translations of British and American works) along with important holdings in other national literatures rank it among the great research libraries. In Catalogue général, Recherches simples allows users to restrict an author, title, keyword, or subject search by type of document. Recherches avancées allows searchers to combine fields (such as author, title, subject, keyword, language, imprint, and performance place) and limit searches by type of document and collection. Recherches spécialisées allows searches by type of document. BnF archives et manuscrits, in progress, can be searched by keyword, shelf mark, name, title, subject, date, and place.

Anyone finding it necessary to consult the printed catalogs should first read Annick Bernard, Guide de l’utilisateur des catalogues des livres imprimés de la Bibliothèque Nationale (Paris: Chadwyck-Healey France, 1986; 60 pp.).

Anyone not holding a current reader pass should consult the Admission to the Reading Rooms and Reader’s Cards Rates page (


Library of Congress Online Catalog. Library of Congress. Lib. of Congress, 2013. 22 Aug. 2013. <>. Updated daily. (The Library of Congress is testing a new search interface.)

A catalog of the print, multimedia, manuscript, and electronic resources held by the Library of Congress; however, some items in collections (e.g., manuscripts) are represented by collection-level catalog records, and some material cataloged before 1980 can be found only through the main card catalog.

Quick Search allows keyword, title keyword, author keyword, or subject keyword seaches. In Basic Search users can search by title, keyword, standard number (LC card number, ISBN, ISSN), author, call number, subject, or series title. Guided Search allows searchers to combine three fields: all those in Basic Search plus publication information, notes, and credits or performers. Clicking Set Search Limits allows users to limit searches by date, language, type of document, LC collection, and place of publication. (Users should note that these limits cannot be set for title, keyword, or standard number searches and that the limits apply to searches in a session until cleared by the user.) Results can be sorted by title (ascending), author (ascending), and date (ascending or descending). When viewing records, users should note where to request a copy (see the “Request in:” line) and remember that holdings information for older records (especially for journals) is not complete. Registered users may use the catalog to request materials for use in the Main, Local History and Genealogy, Science, and Business Reading Rooms.

Public access to the LC online catalog relieves researchers from tedious searches through generally inadequate print records of holdings:

  • Main Catalog of the Library of Congress: Titles Cataloged through December 1980. München: Saur, 1984–89. Microfiche. A reproduction of the author, title, and subject cards for works cataloged by the Library of Congress between c. 1898 and 1980.

  • Library of Congress Shelflist (LC Shelflist). Ann Arbor: Univ. Microfilms Intl., 1979. Supplement, 1978–79. 1980. Microfiche. Since the Shelflist reproduces Library of Congress catalog cards by LC classification number, it offers broad subject access to many works listed in NUC, Pre-56 (E235) and National Union Catalog (E240). Users should be aware that some changes in the classification schedule have resulted in the separation or juxtaposition of subjects in the shelf list. Linda K. Hamilton, ed., The Library of Congress Shelflist: A User’s Guide to the Microfiche Edition, 2 vols. (Ann Arbor: UMI, 1979), provides a basic introduction to the use of the shelf list.

  • Cumulative Title Index to the Library of Congress Shelflist: A Combined Listing of the MARC and REMARC Databases through 1981. 158 vols. Arlington: Carrollton, 1983. Also available on microfiche. A title list of works cataloged by the Library of Congress through 1981.

  • Library of Congress Catalogs: Subject Catalog (LC Subject Catalog). Washington: Lib. of Congress, 1950–83. Quarterly, with annual and quinquennial cumulations. Former title: Library of Congress Catalog: Books: Subjects. Continued by NUC: Books: LC Subject Index (E245).

Anyone using the Library of Congress for the first time should peruse the Information for Researchers page (