Dyfyniad APA

(1987). Thinkers of the twentieth century. Chicago: St. James Press.

Dyfyniad Arddull Chicago

Thinkers of the Twentieth Century. Chicago: St. James Press, 1987.

Dyfyniad MLA

Thinkers of the Twentieth Century. Chicago: St. James Press, 1987.

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