Liu, C. L. Elements of discrete mathematics : A computer oriented approach / by C.L. Liu and D P Mohapatra. - 4th ed. - New York : McGraw-Hill, c1985,2013. - xiv, 627 p. : ill. ; 25 cm. Includes bibliographies and index. ISBN: 9781259006395 Subjects--Topical Terms: Combinatorial analysis.Algebra, Abstract. Dewey Class. No.: 511 / LIU/E