Helen Dwight Reid Educational Foundation. (1971). Journal of Environmental Education. Heldref Publications.
Citação do estilo Chicago (17ª ed.)Helen Dwight Reid Educational Foundation. Journal of Environmental Education. Washington: Heldref Publications, 1971.
Citação MLA (8ª ed.)Helen Dwight Reid Educational Foundation. Journal of Environmental Education. Heldref Publications, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.