by (USSR)A.Starkov;by (United Kingdom)A.Sharp; by (USSR)A.Yariv;by (United Kingdom)J.M.Ziman; by (USSR)I.V.Petrynov;by (United Kingdom)J.G.Stark; by (USSR)A.Starkov;by (United States)K.Sandberg; by (USSR)A.S.Kompaneyets;by (United Kingdom)E.Leader; by (USSR)Ya.A.Smorodinsky;by (United Kingdom)C.Taylor; by (USSR)A.A.Logunov;by (United Kingdom)W.Heisenberg; by (USSR)A.Y.Lebedeva;by (United Kingdom)R.Courtney; by (USSR)G.A.Sudzilovstij;by (United Kingdom)P.R.Webb; by (United States)H.F.Mark;by (United Kingdom)D.W.A.Sharp;