@article{10_4153_CJM_1976_029_0,
     author = {Mather, Michael},
     title = {Pull-Backs in {Homotopy} {Theory}},
     journal = {Canadian journal of mathematics},
     pages = {225--263},
     year = {1976},
     volume = {28},
     number = {2},
     doi = {10.4153/CJM-1976-029-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-029-0/}
}