@article{10_4153_CJM_1991_046_3,
     author = {Piacenza, Robert J.},
     title = {Homotopy {Theory} of {Diagrams} and {CW-Complexes} {Over} a {Category}},
     journal = {Canadian journal of mathematics},
     pages = {814--824},
     year = {1991},
     volume = {43},
     number = {4},
     doi = {10.4153/CJM-1991-046-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1991-046-3/}
}