JEFFREY, R. C. (1967). Formal logic: Its scope and limits. McGraw-Hill.
Chicago-čujuhus (17. p.)JEFFREY, Richard C. Formal Logic: Its Scope and Limits. New York: McGraw-Hill, 1967.
MLA-čujuhus (9. p.)JEFFREY, Richard C. Formal Logic: Its Scope and Limits. McGraw-Hill, 1967.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.