Ives, Ronald L. Climate of the Sonoran desert region, Annals of the Association of American Geographers, Vol. XXXIX, Sept. 1949, pp. 143-187

Ives, Ronald L. Climate of the Sonoran desert region, Annals of the Association of American Geographers, Vol. XXXIX, Sept. 1949, pp. 143-187, Box: 9, Folder: 1. Campbell W. Pennington Papers, 33036864. Benson Latin American Collection, The University of Texas at Austin. https://archives.lib.utexas.edu/repositories/4/archival_objects/279312 Accessed September 26, 2026.