Cita APA (7a ed.)

Ehret, W. F. (1942). Physical science. The Macmillan company.

Cita Chicago Style (17a ed.)

Ehret, William Frederick. Physical Science. New York: The Macmillan company, 1942.

Cita MLA (9a ed.)

Ehret, William Frederick. Physical Science. The Macmillan company, 1942.