@article{DA_1990_30_a0,
     author = {A. A. Ageev},
     title = {A polynomial algorithm for solving the location problem on a series-parallel network},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {3--16},
     publisher = {mathdoc},
     number = {30},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_1990_30_a0/}
}