Gershwin, George, "How Long Has This Been Going On?" from "Smarty," New York, New World [for piano, voice, and ukulele], 1927, Box: 1, Folder: A: 47. Louis and Henry Manners Katzman collection, MS 156. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/416017 Accessed May 10, 2024.