Symbols used in the National Union Catalog of the Library of Congress.
APA Citation
Library of Congress. Union Catalog Division. Symbols used in the National Union Catalog of the Library of Congress. Washington: Library of Congress, Processing Dept., Union Catalog Division.
MLA Citation
Library of Congress. Union Catalog Division. Symbols Used In the National Union Catalog of the Library of Congress. Washington: Library of Congress, Processing Dept., Union Catalog Division,
Warning: These citations may not always be complete (especially for serials).