We report the discovery of three new cases of QSOs acting as strong gravitational lenses on background emission line galaxies : SDSS J0827+5224 ( z _ { QSO } = 0.293 , z _ { s } = 0.412 ) , SDSS J0919+2720 ( z _ { QSO } = 0.209 , z _ { s } = 0.558 ) , SDSS J1005+4016 ( z _ { QSO } = 0.230 , z _ { s } = 0.441 ) .
The selection was carried out using a sample of 22,298 SDSS spectra displaying at least four emission lines at a redshift beyond that of the foreground QSO .
The lensing nature is confirmed from Keck imaging and spectroscopy , as well as from HST/WFC3 imaging in the F475W and F814W filters .
Two of the QSOs have face-on spiral host galaxies and the third is a QSO+galaxy pair .
The velocity dispersion of the host galaxies , inferred from simple lens modeling , is between \sigma = 210 and 285 km s ^ { -1 } , making these host galaxies comparable in mass with the SLACS sample of early-type strong lenses .