HEAO-1 Observations of High Energy X-rays from MKN509 Dil, S. ; Primini, F. ; Byrne, P. ; Dobson, C. ; Doty, J. ; Howe, S. ; Lang, F. ; Levine, A. ; Wheaton, W. A. ; Lewin, W. H. G. ; Baity, W. A. ; Matteson, J. L. ; Peterson, L. E. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: March 1979 Bibcode: 1979BAAS...11..467D