Cita APA (7a ed.)

Liu, C. L., & Liu, C. L. (1968). Introduction to combinatorial mathematics. McGraw-Hill.

Cita Chicago Style (17a ed.)

Liu, C. L., y Chung Laung Liu. Introduction to Combinatorial Mathematics. New York,: McGraw-Hill, 1968.

Cita MLA (8a ed.)

Liu, C. L., y Chung Laung Liu. Introduction to Combinatorial Mathematics. McGraw-Hill, 1968.