@article{DAN_1962_142_2_a2,
     author = {A. P. Ershov and G. I. Kozhukhin},
     title = {Estimates of the chromatic number of connected graphs},
     journal = {Doklady Akademii Nauk},
     pages = {270--273},
     publisher = {mathdoc},
     volume = {142},
     number = {2},
     year = {1962},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_142_2_a2/}
}