Nelson Associates, inc, & Public Library Association. (1969). Public library systems in the United States: A survey of multijurisdictional systems. American Library Association.
Lua i Stíl Chicago (17ú heag.)Nelson Associates, inc, agus Public Library Association. Public Library Systems in the United States: A Survey of Multijurisdictional Systems. Chicago: American Library Association, 1969.
Lua MLA (9ú heag.)Nelson Associates, inc, agus Public Library Association. Public Library Systems in the United States: A Survey of Multijurisdictional Systems. American Library Association, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.