@article{MAIS_2007_14_4_a5,
     author = {R. N. Karasev},
     title = {Genus and the {Lyusternik-Schnirelmann} category of preimages},
     journal = {Modelirovanie i analiz informacionnyh sistem},
     pages = {31--35},
     publisher = {mathdoc},
     volume = {14},
     number = {4},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MAIS_2007_14_4_a5/}
}