@article{IVM_1977_3_a4,
     author = {B. A. Kats},
     title = {Convexity and starlikeness of the level curves of rational {functions.~I}},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {32--42},
     publisher = {mathdoc},
     number = {3},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1977_3_a4/}
}