On the high energy proton spectrum measurements - Ellsworth, R. W.; Ito, A.; Macfall, J.; Siohan, F.; Streitmatter, R. E.; Tonwar, S. C.; Vishwanath, P. R.; Yodh, G. B.; Balasubrahmanyan, V. K. (Springer, 1977)
http://dx.doi.org/10.1007/BF01093876
Keywords: U