Contents of Dr. Wilson Popenoe's Binder of letters received upon retirement (1 of 2), 1957, https://huntbot.org/hibdarc/collections/269/269_EscuelaAgricola_Vol.1_r.pdf. Hunt Institute for Botanical Documentation Archives. https://as.huntbot.org/repositories/2/digital_objects/4405 Accessed June 18, 2026.