Dittmann, H., & Hardy, J. (2007). Learn Library of Congress classification (2nd North American ed.). TotalRecall Publications, Inc..
Cita Chicago (17th ed.)Dittmann, Helena, i Jane Hardy. Learn Library of Congress Classification. 2nd North American ed. Friendswood, Tex: TotalRecall Publications, Inc., 2007.
Cita MLA (9th ed.)Dittmann, Helena, i Jane Hardy. Learn Library of Congress Classification. 2nd North American ed. TotalRecall Publications, Inc., 2007.
Atenció: Aquestes cites poden no estar 100% correctes.