(1975). Map showing bedrock topography and area of occurrence of Madisonville Limestone Member of Sturgis Formation (upper Pennsylvanian) beneath alluvial deposits of the Smith Mills quadrangle, Henderson and Union Counties, Kentucky. U.S. Geological Survey.
Chicago-Zitierstil (17. Ausg.)Map Showing Bedrock Topography and Area of Occurrence of Madisonville Limestone Member of Sturgis Formation (upper Pennsylvanian) Beneath Alluvial Deposits of the Smith Mills Quadrangle, Henderson and Union Counties, Kentucky. Reston, Va: U.S. Geological Survey, 1975.
MLA-Zitierstil (9. Ausg.)Map Showing Bedrock Topography and Area of Occurrence of Madisonville Limestone Member of Sturgis Formation (upper Pennsylvanian) Beneath Alluvial Deposits of the Smith Mills Quadrangle, Henderson and Union Counties, Kentucky. U.S. Geological Survey, 1975.