Não informado. (2022). Report of the Geological Survey of Ohio. Geological Survey of Ohio.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Report of the Geological Survey of Ohio. Columbus, Ohio: Geological Survey of Ohio, 2022.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Report of the Geological Survey of Ohio. Geological Survey of Ohio, 2022.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.