APA

Gray D. E., . (1946). Man and his physical world. New York: D. Van Nostrand Company, inc.

Chicago

Gray Dwight E, . 1946. Man and his physical world. New York: D. Van Nostrand Company, inc.

Harvard

Gray D. E., . (1946). Man and his physical world. New York: D. Van Nostrand Company, inc.

MLA

Gray Dwight E, . Man and his physical world. New York: D. Van Nostrand Company, inc. 1946.