@article{SEMR_2008_5_a20,
     author = {S. A. Puzynina},
     title = {Perfect colorings of radius $r>1$ of the infinite rectangular grid},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {283--292},
     publisher = {mathdoc},
     volume = {5},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2008_5_a20/}
}