@article{DE_1977_13_4_a22,
     author = {E. D. Zhitelzeif},
     title = {Limit cycles of a system of relay type with polynomial right-hand side},
     journal = {Differencialʹnye uravneni\^a},
     pages = {753--755},
     publisher = {mathdoc},
     volume = {13},
     number = {4},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_4_a22/}
}