@article{TAC_2007_18_a20,
     author = {J.S. Milne},
     title = {Quotients of tannakian categories},
     journal = {Theory and applications of categories},
     pages = {654--664},
     publisher = {mathdoc},
     volume = {18},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2007_18_a20/}
}