Cita APA

Freeman, R. A. (1936). The Penrose mystery. Blue Ribbon Books.

Citación estilo Chicago

Freeman, R. Austin. The Penrose Mystery. New York: Blue Ribbon Books, 1936.

Cita MLA

Freeman, R. Austin. The Penrose Mystery. Blue Ribbon Books, 1936.

Warning: These citations may not always be 100% accurate.