Cita APA (7a ed.)

Gruner, E., & Ury, S. (1912). Ex Libris Selma Ury.

Cita Chicago Style (17a ed.)

Gruner, Erich, y Selma Ury. Ex Libris Selma Ury. [S.l.], 1912.

Cita MLA (9a ed.)

Gruner, Erich, y Selma Ury. Ex Libris Selma Ury. 1912.