APA (7th ed.) Citation

Osborn, J., Comaromi, J. P., & Dewey, M. (1991). Dewey decimal classification, 20th edition: A study manual. Libraries Unlimited.

Chicago Style (17th ed.) Citation

Osborn, Jeanne, John P. Comaromi, and Melville Dewey. Dewey Decimal Classification, 20th Edition: A Study Manual. Englewood, CO: Libraries Unlimited, 1991.

MLA (9th ed.) Citation

Osborn, Jeanne, et al. Dewey Decimal Classification, 20th Edition: A Study Manual. Libraries Unlimited, 1991.