@article{TAC_2000_7_a11,
     author = {Enrico M. Vitale},
     title = {Quasi-varieties of presheaves},
     journal = {Theory and applications of categories},
     pages = {236--238},
     year = {2000},
     volume = {7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2000_7_a11/}
}