@article{VMUMM_1991_6_a0,
     author = {O. A. Oleinik},
     title = {On the 90th anniversary of the birth of {Ivan} {Georgievich} {Petrovskii} (1901--1973)},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {3--5},
     publisher = {mathdoc},
     number = {6},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1991_6_a0/}
}