The UCSD/MIT Hard X-Ray and Low Energy γ-Ray Experiment on HEAO-1. Matteson, J. ; Baity, W. ; Gruber, D. ; Knight, F. ; Nolan, P. ; Peterson, L. ; Hoffman, J. ; Lewin, W. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: September 1977 Bibcode: 1977BAAS....9..610M