"San Francisco Road Map and City Map...Hotel Keystone" (San Francisco, CA: Produced by the Keystone Hotel), 1939, Sub-Series 1.4, Box: 9, Folder: 2. Collection of California maps and guidebooks, SC-012. Pfau Library Special Collections. https://archivesspace.csusb.edu//repositories/3/archival_objects/6903 Accessed November 15, 2024.