APA

Berman G., Fryer K. D., . (1972). Introduction to combinatorics. New York and London: Academic Press.

Chicago

Berman Gerald, Fryer Kenneth D, . 1972. Introduction to combinatorics. New York and London: Academic Press.

Harvard

Berman G., Fryer K. D., . (1972). Introduction to combinatorics. New York and London: Academic Press.

MLA

Berman Gerald, Fryer Kenneth D, . Introduction to combinatorics. New York and London: Academic Press. 1972.