United States. Library of Congress. (1990). Library of Congress classification schedules combined with additions and changes through 1989: Class A general works. Gale Research.
Chicago Style (17th ed.) CitationUnited States. Library of Congress. Library of Congress Classification Schedules Combined with Additions and Changes Through 1989: Class A General Works. Detroit: Gale Research, 1990.
MLA (9th ed.) CitationUnited States. Library of Congress. Library of Congress Classification Schedules Combined with Additions and Changes Through 1989: Class A General Works. Gale Research, 1990.
Warning: These citations may not always be 100% accurate.