@article{MM_1991_3_5_a4,
     author = {V. S. Volokitin and N. N. Kalitkin},
     title = {Models of statistic sums for atoms and molecules},
     journal = {Matemati\v{c}eskoe modelirovanie},
     pages = {49--60},
     publisher = {mathdoc},
     volume = {3},
     number = {5},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MM_1991_3_5_a4/}
}