Closing the gap : equal pay for women workers [microfiche] : s. hrg. before the Comm. on Health, Education, Labor, a. Pensions, U. S. Senate, 110th congr., 1st sess., April 18, 2007. - Washington : U.S. Gov. Print. Off., 2009. - 1 microfiche ; 105x148mm.. - (Serial N 110-64)[MFN: 3954]