C. Tsai

Solar Gamma Ray Lines observed during the Solar Activity of August 2 to August 11, 1972

D. Forrest, E. Chupp, P. Higbie, 1973, Nature.

Search for Gamma Ray Lines from Supernovae and Supernova Remnants

D. Forrest, E. Chupp, A. Suri, 1974 .