Copi, I. M., & Cohen, C. (2019). Introduction to Logic (15th.). Routledge.
Chicago-čujuhus (17. p.)Copi, Irving M., juo Carl Cohen. Introduction to Logic. 15th. New York: Routledge, 2019.
MLA-čujuhus (9. p.)Copi, Irving M., juo Carl Cohen. Introduction to Logic. 15th. Routledge, 2019.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.