. . . . . . . . . . . . . "Bridge safety next steps to protect the nation's critical infrastructure : hearing before the Committee on Science and Technology, House of Representatives, One Hundred Tenth Congress, first session, September 19, 2007"@en . . . . "Bridge safety : next steps to protect the nation's critical infrastructure : hearing before the Committee on Science and Technology, House of Representatives, One Hundred Tenth Congress, first session, September 19, 2007"@en .