@article{DE_1973_9_1_a5,
     author = {V. I. Evsin},
     title = {The {Holmgren} problem for a certain equation with singular coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {41--48},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_1_a5/}
}