von Schrenk, Hermann, 1873 1953, Mississippi Valley Laboratory, Vegetable Pathological & Physiological Investigations. books & textbook
The BLUING and the RED ROT of the WESTERN YELLOW PINE, with Special Reference to the Black Hills Forest Reserve. U.S. Department of Agriculture, Bureau of Plant Industry - Bulletin No. 36.
United States Department of Agriculture Washington /1903T Pamphlet
