Cita APA (7th ed.)

Berman, G., & Fryer, K. D. (1972). Introduction to combinatorics. Academic Press.

Cita Chicago (17th ed.)

Berman, Gerald, i K. D. Fryer. Introduction to Combinatorics. Nueva York: Academic Press, 1972.

Cita MLA (9th ed.)

Berman, Gerald, i K. D. Fryer. Introduction to Combinatorics. Academic Press, 1972.