"Principal Automobile Routes of Orange County California" (Orange County, CA; Produced by The Automobile Club of Southern California), Undated, Sub-Series 1.3, Box: 21, Folder: 4. Collection of California maps and guidebooks, SC-012. Pfau Library Special Collections. https://archivesspace.csusb.edu//repositories/3/archival_objects/10505 Accessed November 15, 2024.