McElroy, Frank S. (Frank Shafer) and McCormack, George R. (George Robertson). Injuries and Accident Causes in Fertilizer Manufacturing : a Detailed Analysis of Hazards and Injury-frequency Rates in 1946 by Region, Plant-Size, and Department : Bulletin of the United States Bureau of Labor Statistics, No. 949 , Washington, D.C: U.S. Govt. Print. Off., 1949, https://fraser.stlouisfed.org/title/4375, accessed on November 22, 2024.