Dyfyniad APA

Marshak, S., & Prothero, D. R. (2001). Earth: Portrait of a planet. New York: Norton.

Dyfyniad Arddull Chicago

Marshak, Stephen, và Donald R. Prothero. Earth: Portrait of a Planet. New York: Norton, 2001.

Dyfyniad MLA

Marshak, Stephen, và Donald R. Prothero. Earth: Portrait of a Planet. New York: Norton, 2001.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.