Dyfyniad APA

Oppenheim, E. P. (1923). The seven conundrums. Little, Brown, and Co..

Dyfyniad Arddull Chicago

Oppenheim, E. Phillips. The Seven Conundrums. Boston: Little, Brown, and Co., 1923.

Dyfyniad MLA

Oppenheim, E. Phillips. The Seven Conundrums. Little, Brown, and Co., 1923.

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