@article{DA_1998_5_2_a2,
     author = {A. A. Dobrynin and I. Gutman},
     title = {The {Wiener} index for trees and graphs of hexagonal systems},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {34--60},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_1998_5_2_a2/}
}