Helmle & Helmle, architects
MLA
Russo, Edward J. Helmle & Helmle, Architects. Srpingfield, Ill.: Sangamon County Historical Society, 1974
APA, 7th edition
Russo, E. J. (1974). Helmle & Helmle, architects. Srpingfield, Ill.: Sangamon County Historical Society
Chicago, 17th edition
Russo, Edward J. Helmle & Helmle, architects. Srpingfield, Ill.: Sangamon County Historical Society, 1974