by (Netherlands)P.J.Chen;by (USSR)A.S.Davydov; by (Netherlands)M.Jacob;by (USSR)A.S.Kompaneyets; by (Netherlands)R.Kubo;by (USSR)L.D.Landau; by (Netherlands)B.L.Waerden;by (USSR)A.Yariv; by (Netherlands)V.Ponec;by (USSR)L.Dobrzynski; by (Netherlands)C.V.Westenholz;by (USSR)A.Ramakrishnan; by (Netherlands)J.Dixmier;by (United States)J.R.Durbin; by (Netherlands)J.Gentilli;by (India)E.T.Atkinson; by (Netherlands)M.Benson;by C.M.Schwarz; by (United States)P.Sohar;by (USSR)I.S.Dmitriev;