Liu, C. L. (1985). Elements of discrete mathematics (2nd ed.). McGraw-Hill.
Cita Chicago (17th ed.)Liu, C. L. Elements of Discrete Mathematics. 2nd ed. New York: McGraw-Hill, 1985.
Cita MLA (8th ed.)Liu, C. L. Elements of Discrete Mathematics. 2nd ed. McGraw-Hill, 1985.
Atenció: Aquestes cites poden no estar 100% correctes.