(United Kingdom)D.Ter Haar;by (USSR)V.B.Beresteskii...et al; by (United Kingdom)S.M.Blinder;by (USSR)V.B.Berestetskii...et al; (United Kingdom)O.Watson; (USSR)B.A.Lapidus...et al; by (United Kingdom)D.Tabor;by (USSR)T.Sarpkaya...et al; (United Kingdom)B.Bollobas;by (Netherlands)C.Berge...et al;