(Sweden)G.Berg...et al;by (Federal Republic of Germany)V.I.Arnold; by (Netherlands)C.Berge...et al;by (Federal Republic of Germany)M.Aigner; by (United States)J.T.Clerc...et al;by (Federal Republic of Germany)W.G.Berl; by (United States)H.Eyring...et al;by (Federal Republic of Germany)K.Hubner; by (USSR)J.H.Bater...et al;by (Federal Republic of Germany)G.Fuchs; (United States)J.W.Beattie...et al;by (Federal Republic of Germany)J.Haydn; by (United States)H.J.Emeleus...et al;by (Federal Republic of Germany)V.Gutmann; by (United Kingdom)M.J.Greenberg...et al;by (Federal Republic of Germany)F.Hirzebruch; by (United States)J.F.Uirich...et al;by (Federal Republic of Germany)C.Davis...et al; by (United States)J.Hempel;by (Federal Republic of Germany)V.I.Istratescu;