@article{DE_1987_23_8_a21,
     author = {N. V. Grigorenko},
     title = {Logarithmic singularities of some classical linear differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1455--1457},
     publisher = {mathdoc},
     volume = {23},
     number = {8},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1987_23_8_a21/}
}