Discrete mathematics and its applications / Rosen, Kenneth H. Mathematics. Computer science 511 WCB 1999 A027 Co. Boston : WCB/McGraw-Hill, c1999. c1999. Text xxii, 678 p. : http://www.loc.gov/catdir/description/mh023/98044231.html http://www.loc.gov/catdir/toc/mh022/98044231.html