@article{ZVMMF_1973_13_5_a3,
     author = {A. D. Morozov},
     title = {On the question of the complete qualitative investigation of {Duffing's} equation},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1134--1152},
     publisher = {mathdoc},
     volume = {13},
     number = {5},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1973_13_5_a3/}
}