Cita APA (7a ed.)

Köhler, W. (1941). On the nature of associations. [s.n.].

Cita Chicago Style (17a ed.)

Köhler, Wolfgang. On the Nature of Associations. [S.l.]: [s.n.], 1941.

Cita MLA (9a ed.)

Köhler, Wolfgang. On the Nature of Associations. [s.n.], 1941.