United States. Bureau of Labor Statistics. Compensation Expenditures and Payroll Hours: Pipelines, 1964 : Bulletin of the United States Bureau of Labor Statistics, No. 1528 , Washington, D.C: For sale by the Supt. of Docs., U.S. Govt. Print. Off., April 1967, https://fraser.stlouisfed.org/title/4680, accessed on March 10, 2025.