@article{TAC_2006_16_a25,
     author = {Marco Grandis},
     title = {Quotient models of a category up to directed homotopy},
     journal = {Theory and applications of categories},
     pages = {709--735},
     publisher = {mathdoc},
     volume = {16},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2006_16_a25/}
}