@misc{INTF_1991_81_a0,
     title = {Preface},
     journal = {Itogi Nauki i Tekhniki. Seriya Sovremennye Problemy Matematiki. Fundamental'nye Napravleniya },
     pages = {8--9},
     publisher = {mathdoc},
     volume = {81},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTF_1991_81_a0/}
}