American Library Association. Library Bill of Rights. 1996. http://www.ala.org/advocacy/intfreedom/librarybill

Adopted June 19, 1939, by the ALA Council; amended October 14, 1944; June 18, 1948; February 2, 1961; June 27, 1967; January 23, 1980; inclusion of “age” reaffirmed January 23, 1996.