@article{ZNSL_1967_5_a0,
     author = {V. P. Il'in},
     title = {Preface},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {5},
     publisher = {mathdoc},
     volume = {5},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1967_5_a0/}
}