@article{DA_2006_13_2_a4,
     author = {A. Yu. Chirkov and V. N. Shevchenko},
     title = {On the approximation of an optimal solution of the integer knapsack problem by optimal solutions of the integer knapsack problem with a~restriction on the cardinality},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {56--73},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2006_13_2_a4/}
}