"Mitchell's Crystal Cavers Near Needles, California" (Needles, CA: Produced by the Needles Chamber of Commerce), 1941, Sub-Series 2.3, Box: 17, Folder: 1. Collection of California maps and guidebooks, SC-012. Pfau Library Special Collections. https://archivesspace.csusb.edu//repositories/3/archival_objects/7098 Accessed November 15, 2024.