Railroad architecture

Chicago citation style
Watt, James M., unknown. Railroad architecture. ca. 1972. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/archps/id/2638. (Accessed July 19, 2018.)
APA citation style
Watt, James M., unknown, (ca. 1972) Railroad architecture. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/archps/id/2638
MLA citation style
Watt, James M., unknown. Retrieved from the Digital Public Library of America <http://cdm16786.contentdm.oclc.org/cdm/ref/collection/archps/id/2638>.
Note: These citations are programmatically generated and may be incomplete.