@article{DE_2006_42_1_a13,
     author = {C. Tun\c{c} and E. Tun\c{c}},
     title = {An instability theorem for a class of eighth-order differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {135--138},
     publisher = {mathdoc},
     volume = {42},
     number = {1},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_1_a13/}
}