Cita APA (7a ed.)

Ferstl, J., & Geyer, M. (1907). Ex libris martha geyer.

Cita Chicago Style (17a ed.)

Ferstl, Joseph, y Martha Geyer. Ex Libris Martha Geyer. [S. l.], 1907.

Cita MLA (9a ed.)

Ferstl, Joseph, y Martha Geyer. Ex Libris Martha Geyer. 1907.