@article{DE_1976_12_7_a25,
     author = {N. P. Erugin},
     title = {Nikolaǐ {Evgrafovi\v{c}} {Ko\v{c}in} (on the occasion of the 75th anniversary of his birth)},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1327--1331},
     year = {1976},
     volume = {12},
     number = {7},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_7_a25/}
}