Black Rock Mines #2 and #2

Chicago citation style
Unknown. Black Rock Mines #2 and #2. 1920. Retrieved from the Digital Public Library of America, http://cdm16013.contentdm.oclc.org/cdm/ref/collection/p16013coll3/id/1214. (Accessed July 5, 2020.)
APA citation style
Unknown, (1920) Black Rock Mines #2 and #2. Retrieved from the Digital Public Library of America, http://cdm16013.contentdm.oclc.org/cdm/ref/collection/p16013coll3/id/1214
MLA citation style
Unknown. Retrieved from the Digital Public Library of America <http://cdm16013.contentdm.oclc.org/cdm/ref/collection/p16013coll3/id/1214>.
Note: These citations are programmatically generated and may be incomplete.