@article{TAC_2009_22_a15,
     author = {Daniel G. Davis},
     title = {Epimorphic covers make $R^+_G$ a site, for profinite $G$},
     journal = {Theory and applications of categories},
     pages = {388--400},
     publisher = {mathdoc},
     volume = {22},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2009_22_a15/}
}