NASA's human space exploration [electronic resource] : direction, strategy, and progress : hearing before the Subcommittee on Science and Space of the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Twelfth Congress, first session, November 17, 2011.
Imprint
Washington : U.S. G.P.O. : For sale by the Supt. of Docs., U.S. G.P.O., 2012.