Cita APA (7a ed.)

Fröbes, J. (1912). Psychologia rationalis. [s.n.].

Cita Chicago Style (17a ed.)

Fröbes, Joseph. Psychologia Rationalis. Valkenburg: [s.n.], 1912.

Cita MLA (9a ed.)

Fröbes, Joseph. Psychologia Rationalis. [s.n.], 1912.