@article{BASS_2014_39_1_a2,
     author = {I. Gutman},
     title = {On the origin of two degree - based topological indices},
     journal = {Bulletin de l'Acad\'emie serbe des sciences. Classe des sciences math\'ematiques et naturelles},
     pages = {39 - 52},
     publisher = {mathdoc},
     volume = {39},
     number = {1},
     year = {2014},
     url = {http://geodesic.mathdoc.fr/item/BASS_2014_39_1_a2/}
}