Cita APA (7a ed.)

Popper, K. R. (1989). Objective knowledge: An evolutionary approach ([1st pub., rev. ed.].). Clarendon Press.

Cita Chicago Style (17a ed.)

Popper, Karl Raimund. Objective Knowledge: An Evolutionary Approach. [1st pub., rev. ed.]. Oxford: Clarendon Press, 1989.

Cita MLA (9a ed.)

Popper, Karl Raimund. Objective Knowledge: An Evolutionary Approach. [1st pub., rev. ed.]. Clarendon Press, 1989.