@article{ZNSL_1976_66_a3,
     author = {O. Ya. Viro},
     title = {Nonprojecting isotopies and knots with homeomorphic coverings},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {133--147},
     publisher = {mathdoc},
     volume = {66},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1976_66_a3/}
}