@article{DE_1994_30_7_a2,
     author = {V. I. Gromak and V. V. Tsegel'nik},
     title = {Functional relations between solutions of equations of $P$-type},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1118--1124},
     publisher = {mathdoc},
     volume = {30},
     number = {7},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1994_30_7_a2/}
}