@article{PDM_2013_2_a7,
     author = {V. V. Gotsulenko},
     title = {A formula for the number of combinations with constrained repetitions and its application},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {71--77},
     publisher = {mathdoc},
     number = {2},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2013_2_a7/}
}