@article{DE_1973_9_1_a23,
     author = {M. M. Zainulabidov},
     title = {A certain equation whose order degenerates along the curve of type change},
     journal = {Differencialʹnye uravneni\^a},
     pages = {177--179},
     year = {1973},
     volume = {9},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_1_a23/}
}