@article{DE_1973_9_4_a1,
     author = {N. D. Egupov and A. N. Dmitriev},
     title = {An approximate method of integrating differential equations with polynomial coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {609--613},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_4_a1/}
}