Não informado. (2018). Reprint Series. Geological Survey of Ohio.
Chicago (17e ed.) BronvermeldingNão informado. Reprint Series. Columbus, Ohio: Geological Survey of Ohio, 2018.
MLA (8e ed.) BronvermeldingNão informado. Reprint Series. Geological Survey of Ohio, 2018.
Let op: Deze citaties zijn niet altijd 100% accuraat.