@article{TAC_2002_10_a13,
     author = {Marco Grandis},
     title = {Directed homotopy theory, {II.} {Homotopy} constructs},
     journal = {Theory and applications of categories},
     pages = {369--391},
     publisher = {mathdoc},
     volume = {10},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2002_10_a13/}
}