@article{TM_1968_98_a0,
     author = {V. P. Orevkov},
     title = {Preface},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {3--4},
     publisher = {mathdoc},
     volume = {98},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1968_98_a0/}
}