Murray, Roland V. Labor and Material Requirements for Civil Works Construction by the Corps of Engineers : Bulletin of the United States Bureau of Labor Statistics, No. 1390 , Washington: U.S. Dept. of Labor, Bureau of Labor Statistics; for sale by the Superintendent of Documents, U.S. Govt. Print. Off., March 1964, https://fraser.stlouisfed.org/title/4930, accessed on October 12, 2024.