@article{ZNSL_1973_31_a0,
     author = {B. B. Venkov},
     title = {Preface},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {5},
     year = {1973},
     volume = {31},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1973_31_a0/}
}