@article{DOCMA_2008__13__a15,
     author = {Kumjian, Alex and Pask, David and Sims, Aidan},
     title = {$C^*$-algebras associated to coverings of $k$-graphs},
     journal = {Documenta mathematica},
     pages = {161--205},
     publisher = {mathdoc},
     volume = {13},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DOCMA_2008__13__a15/}
}