Multiwavelength Observations of Ultrasoft X-Ray Emitting Active Galactic Nuclei Thompson, R. J., Jr. ; Córdova, F. A. ; Puchnarewicz, E. M. ; Mason, K. O. Abstract Publication: American Astronomical Society Meeting Abstracts #180 Pub Date: May 1992 Bibcode: 1992AAS...180.0210T