Não informado. (1889). Bulletin of the Geological and Natural History Survey of Minnesota. Geological and Natural History Survey of Minnesota.
Chicago-Zitierstil (17. Ausg.)Não informado. Bulletin of the Geological and Natural History Survey of Minnesota. Minneapolis, Minn: Geological and Natural History Survey of Minnesota, 1889.
MLA-Zitierstil (8. Ausg.)Não informado. Bulletin of the Geological and Natural History Survey of Minnesota. Geological and Natural History Survey of Minnesota, 1889.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.