Beach, J.R. "The effect of feeding bacillus acidophilus, lactose, dry skim milk, or whole milk on the hydrogen ion concentration of the contents of the ceca of chickens." Hilgardia: A Journal of Agricultural Science published by the California agricultural experiment station, October 1925.

Beach, J.R. "The effect of feeding bacillus acidophilus, lactose, dry skim milk, or whole milk on the hydrogen ion concentration of the contents of the ceca of chickens." Hilgardia: A Journal of Agricultural Science published by the California agricultural experiment station, October 1925., Box: 1. Veterinary Reprint and Pamphlet Collection, 24-4-3369. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/262313 Accessed December 20, 2025.