Observation of Gamma Radiation from the Crab Nebula Haymes, R. C. ; Ellis, D. V. ; Fishman, G. J. ; Kurfess, J. D. ; Tucker, W. H. Abstract Publication: The Astrophysical Journal Pub Date: January 1968 DOI: 10.1086/180129 Bibcode: 1968ApJ...151L...9H