The key resource for researching why a particular title was challenged or banned are the publications of ALA's Office for Intellectual Freedom. The Office maintains information on which books are challenged and why and regularly publishes this information in the Journal of Intellectual Freedom and Privacy, where there may also be discussion of the events surrounding a challenge, and in a compilation published about every three years, most recently in Banned Books: Defending our Freedom to Read, edited by Robert P. Doyle. (Before 2016, similar information was in the Newsletter on Intellectual Freedom.)
Doyle and others used histories of censorship to compile the initial listing of challenged or banned books; this bibliography is in the Guide, as well as included on a list of books on censorship maintained by the ALA Library.
More recent entries are derived from the Journal of Intellectual Freedom and Privacy or Newsletter on Intellectual Freedom.
This publication is available in many libraries around the country, or may be ordered from the ALA Store..
