"This cumulation includes the revisions to July 1964 ... and the revisions published in LC Classification-additions and changes, list 135 (July-Sept.,1964) through list 248 (Oct.-Dec.,1992)" - t.p. verso.
Revisions to: Classification: class P, subclass PG (in part) Russian literature. Washington: Library of Congress, 1948.
Library of Congress classification schedules : a cumulation of additions and changes through 1992. Class P, subclass PG (in part), Russian literature. ISBN 0810382504. Published by Gale Research in 1993. Publication and catalogue information, links to buy online and reader comments.