Mechanical Contractors Association of America (MCAA), Labor Estimating Manual: Appendix B, Factors Affecting Productivity, Rockville, Md., August 1998.

National Electrical Contractors Association (NECA), Manual of Labor Units, Bethesda, Md., 1976 and 2003.

U.S. Army Corps of Engineers, Modification Impact Evaluation Guide, EP 415-1-3, Department of the Army, Office of the Chief of Engineers, Washington, D.C., July, 1979.53

Source: AACE International Recommended Practice No. 25R-03 - Estimating Lost Labor Productivity in Construction Claims