Dyfyniad APA

Macdougall, J. D. (2013). Frozen earth: The once and future story of ice ages. University of California Press.

Dyfyniad Arddull Chicago

Macdougall, J. D. Frozen Earth: The Once and Future Story of Ice Ages. Berkeley: University of California Press, 2013.

Dyfyniad MLA

Macdougall, J. D. Frozen Earth: The Once and Future Story of Ice Ages. University of California Press, 2013.

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