38 books
Illustrations to the Geological Report of Wisconsin, Iowa, and Minnesota (Classic Reprint)
Reports on the Geology of the Tunungwant Coal Field, m'Kean County, Pa (Classic Reprint)
Report of the Geological Survey in Kentucky, Made During the Years ... and ..., Volume 3
First-Fourth Report of the Geological Survey in Kentucky Made During the Years 1854 to 1859