Dyfyniad APA

National Geographic Society. (2002). McGraw-Hill science. New York: McGraw-Hill.

Dyfyniad Arddull Chicago

National Geographic Society. McGraw-Hill Science. New York: McGraw-Hill, 2002.

Dyfyniad MLA

National Geographic Society. McGraw-Hill Science. New York: McGraw-Hill, 2002.

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