Dan Sanborn's Rio Grande Valley Letter. McAllen, Texas: Vandever's Letter Shop, August 23, 1947

Dan Sanborn's Rio Grande Valley Letter. McAllen, Texas: Vandever's Letter Shop, August 23, 1947, Volume: Gilbert E310. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/525722 Accessed December 26, 2025.