@article{1102734960,
author = {Zuckerman, Martin M.},
title = {Choosing $l$-element subsets of $n$-element sets.},
journal = {Pacific J. Math.},
volume = {97},
number = {2},
year = {1981},
pages = { 247-250},
language = {en},
url = {http://dml.mathdoc.fr/item/1102734960}
}
Zuckerman, Martin M. Choosing $l$-element subsets of $n$-element sets.. Pacific J. Math., Tome 97 (1981) no. 2, pp. 247-250. http://gdmltest.u-ga.fr/item/1102734960/