Silurian

Chicago citation style
Maryland Geological Survey. Silurian. 1923. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/001661599. (Accessed November 16, 2018.)
APA citation style
Maryland Geological Survey, (1923) Silurian. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/001661599
MLA citation style
Maryland Geological Survey. Retrieved from the Digital Public Library of America <http://catalog.hathitrust.org/Record/001661599>.
Note: These citations are programmatically generated and may be incomplete.