Krishan Kumar; Author. (1997). Theory of classification (Ed.4 rev.).
Chicago Style aipamenaKrishan Kumar; Author. Theory of Classification. Ed.4 rev. New Delhi, Vikas Publishing, 1997.
MLA aipamenaKrishan Kumar; Author. Theory of Classification. Ed.4 rev. 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.