Dyfyniad APA

Sagan, C. (2013). Cosmos (Ballantine Books Trade Paperbacks, 2013.). Ballantine.

Dyfyniad Arddull Chicago

Sagan, Carl. Cosmos. Ballantine Books Trade Paperbacks, 2013. New York: Ballantine, 2013.

Dyfyniad MLA

Sagan, Carl. Cosmos. Ballantine Books Trade Paperbacks, 2013. Ballantine, 2013.

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