@article{1102817363,
author = {Feder, S. and Gitler, S. and Lam, K. Y.},
title = {Composition properties of projective homotopy classes.},
journal = {Pacific J. Math.},
volume = {73},
number = {2},
year = {1977},
pages = { 47-61},
language = {en},
url = {http://dml.mathdoc.fr/item/1102817363}
}
Feder, S.; Gitler, S.; Lam, K. Y. Composition properties of projective homotopy classes.. Pacific J. Math., Tome 73 (1977) no. 2, pp. 47-61. http://gdmltest.u-ga.fr/item/1102817363/