@article{DE_1971_7_7_a3,
     author = {N. A. Izobov},
     title = {Cases of sharpening and the attainability of an estimate of the highest exponent in the method of freezing},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1179--1191},
     publisher = {mathdoc},
     volume = {7},
     number = {7},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1971_7_7_a3/}
}