APA-viite (7. p.)

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

Chicago-viite (17. p.)

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

MLA-viite (9. p.)

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