Não informado. (1982). National Water Conditions. U.S. Department of the Interior, Geological Survey.
Chicago-Zitierstil (17. Ausg.)Não informado. National Water Conditions. Reston, Va: U.S. Department of the Interior, Geological Survey, 1982.
MLA-Zitierstil (8. Ausg.)Não informado. National Water Conditions. U.S. Department of the Interior, Geological Survey, 1982.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.