Copi, I. M., & Cohen, C. (2019). Introduction to Logic (15th.). Routledge.
Lua i Stíl Chicago (17ú heag.)Copi, Irving M., agus Carl Cohen. Introduction to Logic. 15th. New York: Routledge, 2019.
Lua MLA (9ú heag.)Copi, Irving M., agus Carl Cohen. Introduction to Logic. 15th. Routledge, 2019.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.