United States. Congress. Senate. Committee on Labor and Human Resources.
Washington : U.S. G.P.O. : For sale by the Supt. of Docs., Congressional Sales Office, U.S. G.P.O., 1986.
National Research Council (U.S.). Committee on Science Opportunities Enabled by NASA's Constellation System.
Washington, D.C. : National Academies Press, [2009]