@book{ Solr-7713245, title = {Map of the Sanitary District of Chicago showing dilution system and sewage treatment projects.}, series = {Government maps of Chicago in the 1920s, 1930s, and 1940s.}, series = {University of Chicago Digital Preservation Collection.}, address = {Chicago}, publisher = {Sanitary District?]}, year = {1931}, url = {http://pi.lib.uchicago.edu/1001/maps/chigov/G4104-C6N46-1931-M2} }