@article{IVM_1963_5_a6,
     author = {V. N. Karp},
     title = {On the existence and uniqueness of a periodic solution of a non-linear equation of hyperbolic type},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {43--50},
     publisher = {mathdoc},
     number = {5},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1963_5_a6/}
}