Cita APA (7a ed.)

Fries, H. (1963). CREER Y SABER. Guadarrama.

Cita Chicago Style (17a ed.)

Fries, Heinrich. CREER Y SABER. Madrid: Guadarrama, 1963.

Cita MLA (9a ed.)

Fries, Heinrich. CREER Y SABER. Guadarrama, 1963.