HEAO-1 Observations of High-Energy X-rays from the Galactic Center Region Matteson, J. ; Gruber, D. ; Nolan, P. ; Proctor, R. ; Peterson, L. ; Levine, A. ; Primini, F. ; Lewin, W. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: March 1981 Bibcode: 1981BAAS...13..867M