@article{DA_2013_20_1_a1,
     author = {A. I. Erzin and R. V. Plotnikov and Yu. V. Shamardin},
     title = {Some polynomially solvable cases and approximation algorithms for optimal communication tree construction problem},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {12--27},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2013_20_1_a1/}
}