@article{DA_2011_18_1_a4,
     author = {V. P. Il'ev and S. D. Il'eva and A. A. Navrotskaya},
     title = {Approximation algorithms for graph approximation problems},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {41--60},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2011_18_1_a4/}
}