Schmidt, Maarten; Schneider, Donald; Gunn, James. Spectrscopic CCD Surveys for Quasars at Large Redshift.IV.Evolution of the Luminosity Function from Quasars Detected by Their Lyman-Alpha Emission. The Astronomical Journal. 1995, 110: 68. Bibcode:1995AJ....110...68S. doi:10.1086/117497.
Schmidt, Maarten; Schneider, Donald; Gunn, James. Spectrscopic CCD Surveys for Quasars at Large Redshift.IV.Evolution of the Luminosity Function from Quasars Detected by Their Lyman-Alpha Emission. The Astronomical Journal. 1995, 110: 68. Bibcode:1995AJ....110...68S. doi:10.1086/117497.