• [1]

    J.R.Ren et al.,Phys.Rev.,D38(1988)1404;C.M.G.Lattes et al.,Phys.Rep.,65(1980)151.[2]M.Shibata,18th ICRC Banghore 11(1983)106.[3]China-Japan Emulsion Chamber Collaboration,19th ICRC 6(1985)313,317.