(left to right): Charles Gordon Curtis (1860-1953) and Paul Henry Schweitzer (1893-1980)

Chicago citation style
(left to right): Charles Gordon Curtis (1860-1953) and Paul Henry Schweitzer (1893-1980). Retrieved from the Digital Public Library of America, http://collections.si.edu/search/results.htm?q=record_ID%3Asiris_arc_296603&repo=DPLA. (Accessed November 20, 2018.)
APA citation style
(left to right): Charles Gordon Curtis (1860-1953) and Paul Henry Schweitzer (1893-1980). Retrieved from the Digital Public Library of America, http://collections.si.edu/search/results.htm?q=record_ID%3Asiris_arc_296603&repo=DPLA
MLA citation style
Retrieved from the Digital Public Library of America <http://collections.si.edu/search/results.htm?q=record_ID%3Asiris_arc_296603&repo=DPLA>.
Note: These citations are programmatically generated and may be incomplete.