The following libraries mentioned the Lorax's challenge: Kansas City, Kansas Public Library: During the banned books week the Lorax was mentioned as a challenged book at this library. http://www.kckpl.lib.ks.us/YS/books/banned.htm Longview, Washington Public Library: The Lorax was discussed in an article by the Longview, Washington Public Library about challenged books. http://www.longviewlibrary.org/Teens.html Mansfield University Library: Mansfield Unversity has a collection of banned books in its library that includes the Lorax. http://lib.mansfield.edu/banned.cfm The following websites mentioned the Lorax's challenge: http://www.progressiveu.org/194842-banned-books-and- points This source compiled many banned books on one list and the Lorax is on this list. http://homepages.luc.edu/~vcrouth/banned.htm This site has a table that is composed of banned books. One of the banned books mentioned is the Lorax.