Dyfyniad APA

North, J. (1995). The Norton history of Astronomy and cosmology. New York: W.W.Norton & Company.

Dyfyniad Arddull Chicago

North, John. The Norton History of Astronomy and Cosmology. New York: W.W.Norton & Company, 1995.

Dyfyniad MLA

North, John. The Norton History of Astronomy and Cosmology. New York: W.W.Norton & Company, 1995.

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