@article{GDZPPN002231662,
title = {The sigma-core of a cooperative game.},
journal = {Manuscripta mathematica},
volume = {70},
year = {1991},
pages = {247-254},
zbl = {0737.90081},
url = {http://dml.mathdoc.fr/item/GDZPPN002231662}
}
Parker, June M. The sigma-core of a cooperative game.. Manuscripta mathematica, Tome 70 (1991) pp. 247-254. http://gdmltest.u-ga.fr/item/GDZPPN002231662/