Não informado. (2002). Parks & Recreation. American Institute of Park Executives.
Chicago-referens (17:e uppl.)Não informado. Parks & Recreation. Wheeling, Ill: American Institute of Park Executives, 2002.
MLA-referens (8:e uppl.)Não informado. Parks & Recreation. American Institute of Park Executives, 2002.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.