Citazione Stile APA (7a Edizione)

Montgomery, C. W. (1994). Earth then and now (2nd ed.). Wm. C. Brown Publishers.

Citazione stile Chigago Style (17a edizione)

Montgomery, Carla W. Earth Then and Now. 2nd ed. Dubuque, IA: Wm. C. Brown Publishers, 1994.

Citatione MLA (9a ed.)

Montgomery, Carla W. Earth Then and Now. 2nd ed. Wm. C. Brown Publishers, 1994.