Não informado. (1982). National Water Conditions. U.S. Department of the Interior, Geological Survey.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. National Water Conditions. Reston, Va: U.S. Department of the Interior, Geological Survey, 1982.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. National Water Conditions. U.S. Department of the Interior, Geological Survey, 1982.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.