Não informado. (1931). Geological Bulletin. Department of Conservation, Geological Survey.
Chicago-Zitierstil (17. Ausg.)Não informado. Geological Bulletin. New Orleans, La: Department of Conservation, Geological Survey, 1931.
MLA-Zitierstil (8. Ausg.)Não informado. Geological Bulletin. Department of Conservation, Geological Survey, 1931.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.