Cita APA (7th ed.)

O'Hear, A. (1980). Karl Popper. Routledge & Kegan Paul.

Cita Chicago (17th ed.)

O'Hear, Anthony. Karl Popper. London: Routledge & Kegan Paul, 1980.

Cita MLA (9th ed.)

O'Hear, Anthony. Karl Popper. Routledge & Kegan Paul, 1980.