Dyfyniad APA

SIMPSON, G. G. (1964). Life of the past: An introductionto paleontology. YaleUniversity.

Dyfyniad Arddull Chicago

SIMPSON, George Gaylord. Life of the Past: An Introductionto Paleontology. London: YaleUniversity, 1964.

Dyfyniad MLA

SIMPSON, George Gaylord. Life of the Past: An Introductionto Paleontology. YaleUniversity, 1964.

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