Cita APA (7a ed.)

Krahl, E. A., & Ammann, A. F. (1890). Ex-Libris August F. Ammann.

Cita Chicago Style (17a ed.)

Krahl, Ernst August, y August Ferdinand Ammann. Ex-Libris August F. Ammann. [S. l, 1890.

Cita MLA (9a ed.)

Krahl, Ernst August, y August Ferdinand Ammann. Ex-Libris August F. Ammann. 1890.