@article{03979382,
title = {The semigroup of nonempty finite subsets of integers.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {9},
year = {1986},
pages = {605-616},
doi = {10.1155/S0161171286000765},
zbl = {0606.20057},
language = {en},
url = {http://dml.mathdoc.fr/item/03979382}
}
Spake, Reuben. The semigroup of nonempty finite subsets of integers.. International Journal of Mathematics and Mathematical Sciences, Tome 9 (1986) pp. 605-616. doi : 10.1155/S0161171286000765. http://gdmltest.u-ga.fr/item/03979382/