@article{ZNSL_1968_9_a0,
     author = {V. M. Babich},
     title = {Preface},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {3--4},
     publisher = {mathdoc},
     volume = {9},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1968_9_a0/}
}