Παραπομπή APA

(1980). Books in print 1980-81. R.R. Bowker Company.

Παραπομπή Chicago Style

Books in Print 1980-81. New York: R.R. Bowker Company, 1980.

Παραπομπή MLA

Books in Print 1980-81. R.R. Bowker Company, 1980.