Cita APA (7a ed.)

Becker, A., & Krenn, W. (1961). Geographie. Leitner.

Cita Chicago Style (17a ed.)

Becker, Anton, y Walther Krenn. Geographie. Wels [u.a.]: Leitner, 1961.

Cita MLA (9a ed.)

Becker, Anton, y Walther Krenn. Geographie. Leitner, 1961.