Barker, S. F. (1980). The elements of logic (3rd ed.). McGraw-Hill.
Cita Chicago (17th ed.)Barker, Stephen F. The Elements of Logic. 3rd ed. New York: McGraw-Hill, 1980.
Cita MLA (9th ed.)Barker, Stephen F. The Elements of Logic. 3rd ed. McGraw-Hill, 1980.
Atenció: Aquestes cites poden no estar 100% correctes.