@article{DE_1968_4_11_a11,
     author = {V. P. Prokop'ev},
     title = {On the stability of systems with aftereffect in the critical case of two zero roots},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2027--2033},
     publisher = {mathdoc},
     volume = {4},
     number = {11},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_11_a11/}
}