Observation of periodic gamma radiation from the discrete source Cygnus X-3 Gal'Per, A. M. ; Kirillov-Ugryumov, V. G. ; Kurochkin, A. V. ; Leikov, N. G. ; Luchkov, B. I. ; Yurkin, Yu. T. Abstract Publication: Soviet Journal of Experimental and Theoretical Physics Letters Pub Date: September 1977 Bibcode: 1977JETPL..26..259G