found: Its Books of the Americas.
found: The Five-Year plans of the Chicago Public Library and the Chicago Library System, 1979-1983, 1980:t.p. (Chicago Public Library/Chicago Library System) p. 42 (Chicago Library System (CLS) was est. 1965; Chicago Public Library/Chicago Library System (CPL/CLS) is unique in Illinois in that it is both a public library and a library system; CPL and CLS governance and administration are identical)
found: Illinois libraries, Dec. 2005 via WWW, 6/13/2011p. 88 ("On July 1, 2003, CLS became The Chicago Multi Type Library System. The Board was changed to reflect the membership: academic, special and school; Chicago Public Library legally separated from the multi type CLS")
found: Illinois State Library website, viewed 6/14/2011library system page (Chicago Public Library System is its own public library system)