Cita APA (7th ed.)
Copi, I. M., & Cohen, C. (2009). Introduction to logic (13th ed.). Pearson/Prentice Hall.
Cita Chicago (17th ed.)
Copi, Irving M., i Carl Cohen. Introduction to Logic. 13th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2009.
Cita MLA (9th ed.)
Copi, Irving M., i Carl Cohen. Introduction to Logic. 13th ed. Pearson/Prentice Hall, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.