The minerals of Pennsylvania : non-metallic minerals / by R.W. Stone.

Chicago citation style
Stone, Ralph W. (Ralph Walter), 1876-1964. The minerals of Pennsylvania : non-metallic minerals / by R.W. Stone.. Retrieved from the Digital Public Library of America, https://archive.org/details/mineralsofpennsy00ston. (Accessed December 14, 2018.)
APA citation style
Stone, Ralph W. (Ralph Walter), 1876-1964, The minerals of Pennsylvania : non-metallic minerals / by R.W. Stone.. Retrieved from the Digital Public Library of America, https://archive.org/details/mineralsofpennsy00ston
MLA citation style
Stone, Ralph W. (Ralph Walter), 1876-1964. Retrieved from the Digital Public Library of America <https://archive.org/details/mineralsofpennsy00ston>.
Note: These citations are programmatically generated and may be incomplete.