@article{DA_2009_16_6_a3,
     author = {D. S. Malyshev},
     title = {On minimal hard classes of graphs},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {43--51},
     publisher = {mathdoc},
     volume = {16},
     number = {6},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2009_16_6_a3/}
}