TY  - JOUR
AU  - Hardie, K. A.
TI  - Homotopy of Natural Transformations
JO  - Canadian journal of mathematics
PY  - 1970
SP  - 332
EP  - 341
VL  - 22
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-041-2/
DO  - 10.4153/CJM-1970-041-2
ID  - 10_4153_CJM_1970_041_2
ER  -