@article{VMP_2013_14_1_a1,
     author = {I. L. Vasiliev and A. V. Ushakov},
     title = {A parallel implementation of the subgradient algorithm for maximizing the {Lagrangian} dual function in the $p$-median problem},
     journal = {Numerical methods and programming},
     pages = {9--16},
     publisher = {mathdoc},
     volume = {14},
     number = {1},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2013_14_1_a1/}
}