Cita APA

Gray, D. E. Man and his Physical World. / Dwight E. Gray (2.). Toronto : D. Van Nostrand Company.

Citación estilo Chicago

Gray, Dwight E. Man and His Physical World. / Dwight E. Gray. 2. Toronto : D. Van Nostrand Company.

Cita MLA

Gray, Dwight E. Man and His Physical World. / Dwight E. Gray. 2. Toronto : D. Van Nostrand Company.