Citation:
Ryan J, Forrest D, McConnell M, Collmar W, Schönfelder V, Steinle H, Strong A, van Dijk R, Hermsen W, Bennett K, et al. A High Sensitivity Measurement of the γ-ray Spectrum of Cygnus X-1 Near 1 MeV, in American Astronomical Society Meeting Abstracts. Vol 27. ; 1994 :772–772.