@article{TAC_2015_30_a16,
     author = {Ernie Manes},
     title = {Extensive categories and the size of an orbit},
     journal = {Theory and applications of categories},
     pages = {599--619},
     publisher = {mathdoc},
     volume = {30},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2015_30_a16/}
}