Vol. s3-15, Issue 90, 1878June 01, 1878 EDT
The Upper Devonian Rocks of Southwest Pennsylvania
The Upper Devonian Rocks of Southwest Pennsylvania
John James Stevenson,
Stevenson, J. J. (1878). The upper Devonian rocks of southwest Pennsylvania. American Journal of Science, s3-15(90), 423–430. https://doi.org/10.2475/ajs.s3-15.90.423