"Contra Costa County Modern Section Chevron" (Contra Costa, CA: Produced by The H. M. Gousha Company), 1971, Sub-Series 1.1, Box: 2, Folder: 1. Collection of California maps and guidebooks, SC-012. Pfau Library Special Collections. https://archivesspace.csusb.edu//repositories/3/archival_objects/6684 Accessed November 15, 2024.