Não informado. Topographic and Geologic Atlas of Pennsylvania. Pennsylvania Geological Survey.
Chicagoスタイル(17版)引用形式Não informado. Topographic and Geologic Atlas of Pennsylvania. Harrisburg, Pa: Pennsylvania Geological Survey.
MLA(8版)引用形式Não informado. Topographic and Geologic Atlas of Pennsylvania. Pennsylvania Geological Survey.
警告: この引用は必ずしも正確ではありません.