Cita APA (7a ed.)

Wenig, B., & Heraeus, W. C. (1902). Ex Libris Wilhelm Carl Heraeus.

Cita Chicago Style (17a ed.)

Wenig, Bernhard, y Wilhelm Carl Heraeus. Ex Libris Wilhelm Carl Heraeus. [S.l.], 1902.

Cita MLA (9a ed.)

Wenig, Bernhard, y Wilhelm Carl Heraeus. Ex Libris Wilhelm Carl Heraeus. 1902.