APA (7th ed.) Zitazioa

POPPER, K. R. (1979). Objective knowledge: An evolutionary approach (2nd ed.). Clarendon.

Chicago Style (17th ed.) Zitazioa

POPPER, Karl R. Objective Knowledge: An Evolutionary Approach. 2nd ed. Oxford: Clarendon, 1979.

MLA (9th ed.) Zitazioa

POPPER, Karl R. Objective Knowledge: An Evolutionary Approach. 2nd ed. Clarendon, 1979.