Dyfyniad APA
Copi, I. M., & Cohen, C. (2002). Introduction to logic (11th ed.). Prentice Hall.
Dyfyniad Arddull Chicago
Copi, Irving M., and Carl Cohen. Introduction to Logic. 11th ed. Upper Saddle River, N.J. : New Delhi: Prentice Hall, 2002.
Dyfyniad MLA
Copi, Irving M., and Carl Cohen. Introduction to Logic. 11th ed. Prentice Hall, 2002.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.