Helen Dwight Reid Educational Foundation. (1971). Journal of Environmental Education. Heldref Publications.
Chicago-referens (17:e uppl.)Helen Dwight Reid Educational Foundation. Journal of Environmental Education. Washington: Heldref Publications, 1971.
MLA-referens (8:e uppl.)Helen Dwight Reid Educational Foundation. Journal of Environmental Education. Heldref Publications, 1971.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.