@article{DE_1965_1_8_a0,
     author = {I. T. Kiguradze},
     title = {On the question of variability of solutions of nonlinear differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {995--1006},
     publisher = {mathdoc},
     volume = {1},
     number = {8},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1965_1_8_a0/}
}