Cita APA (7th ed.)

Grasskamp, W. (1997). Philosophical Platform. Bert Theis : some works.

Cita Chicago (17th ed.)

Grasskamp, Walter. "Philosophical Platform." Bert Theis : Some Works 1997.

Cita MLA (8th ed.)

Grasskamp, Walter. "Philosophical Platform." Bert Theis : Some Works, 1997.