More Seyfert Galaxy X-Ray Sources Observed with the HEAO-1 Modulation Collimator Dower, R. ; Griffiths, R. ; Johnston, M. ; Bradt, H. ; Doxsey, R. ; Schwartz, D. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: March 1979 Bibcode: 1979BAAS...11..442D