Gordon, C. E., & Hindman, N. (1975). Elementary set theory: Proof techniques. Hafner.
Chicago Style (17th ed.) CitationGordon, Carl E., and Neil Hindman. Elementary Set Theory: Proof Techniques. New York: Hafner, 1975.
MLA (9th ed.) CitationGordon, Carl E., and Neil Hindman. Elementary Set Theory: Proof Techniques. Hafner, 1975.
Warning: These citations may not always be 100% accurate.