@article{DE_1977_13_5_a16,
     author = {A. F. Andreev and I. V. Pehenko},
     title = {A system with one zero root of the characteristic equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {944--946},
     publisher = {mathdoc},
     volume = {13},
     number = {5},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_5_a16/}
}