Panama Canal towing locomotive descending an incline, ca. 1921

Chicago citation style
Unknown. Panama Canal towing locomotive descending an incline, ca. 1921. unknown. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ic/id/301. (Accessed July 17, 2018.)
APA citation style
Unknown, (unknown) Panama Canal towing locomotive descending an incline, ca. 1921. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ic/id/301
MLA citation style
Unknown. Retrieved from the Digital Public Library of America <http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ic/id/301>.
Note: These citations are programmatically generated and may be incomplete.