@article{DE_1970_6_8_a11,
     author = {V. R. Portnov},
     title = {The integral representation of functions by an ordinary differential operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1424--1438},
     year = {1970},
     volume = {6},
     number = {8},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_8_a11/}
}