Mellanby, J. receipt for Prain, David Sir (1857–1944), 7 February 1924, Box: 3, Folder: 29. William Winfield Ray collection of 20th century botanists correspondence and other materials, HIBDARC-0048. Hunt Institute for Botanical Documentation Archives. https://as.huntbot.org/repositories/2/archival_objects/3907 Accessed March 20, 2026.