Chance, H. M. (1879). The northern Townships of Butler County: Part first. Board of Commissioners for the Second Geological Survey.
Chicago-Zitierstil (17. Ausg.)Chance, Henry Martyn. The Northern Townships of Butler County: Part First. Harrisburg: Board of Commissioners for the Second Geological Survey, 1879.
MLA-Zitierstil (9. Ausg.)Chance, Henry Martyn. The Northern Townships of Butler County: Part First. Board of Commissioners for the Second Geological Survey, 1879.
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