Não informado. (1972). Ecological Research Series. U.S. Environmental Protection Agency.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Ecological Research Series. Washington: U.S. Environmental Protection Agency, 1972.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Ecological Research Series. U.S. Environmental Protection Agency, 1972.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.