The license agreement is (copied and pasted from the download page):
Copyright 1996 by A K Peters, Ltd.
Reproduction of the downloaded version is permitted for any valid
educational purpose of an institution of learning, in which case only
the reasonable costs of reproduction may be charged. Reproduction for
profit or for any commercial purposes is strictly prohibited.
http://www.math.upenn.edu/~wilf/AeqB.pdf
http://www.math.rutgers.edu/~zeilberg/AeqB.pdf
http://www.fmf.uni-lj.si/aeqb/AeqB.pdf
The license agreement is (copied and pasted from the download page):