Cita APA (7th ed.)

Montgomery, C. W. (1997). Earth then and now (3rd ed.). Wm. C. Brown Publishers.

Cita Chicago (17th ed.)

Montgomery, Carla W. Earth Then and Now. 3rd ed. Dubuque, IA: Wm. C. Brown Publishers, 1997.

Cita MLA (9th ed.)

Montgomery, Carla W. Earth Then and Now. 3rd ed. Wm. C. Brown Publishers, 1997.