The manuscript title is "The effects of subsity of Presbyterian Churches", by Henry Hughes Presler, and can be found at Mansueto Library, University of Chicago under the call number BX 10999. These maps have been outlined and vectorized as the originals, and points placed for location of churches as they were in the original. Call number for the maps: G4104.C6E1 1948.H6. Map Collection, Regenstein Library, University of Chicago. Drawn from Map 7 - Location of Presbyterian churches in relation to ethnic groups in the city of Chicago, by Census Tracts, 1920.