Cita APA (7a ed.)

Petzall, A. (1935). Theoria. Blackwell.

Cita Chicago Style (17a ed.)

Petzall, Ake. Theoria. Oxford [etc.]: Blackwell, 1935.

Cita MLA (9a ed.)

Petzall, Ake. Theoria. Blackwell, 1935.