@article{GDZPPN002288583,
title = {Operators and Cooperators in Homotopy Theory.},
journal = {Mathematische Annalen},
volume = {141},
year = {1960},
pages = {1-21},
zbl = {0094.17301},
url = {http://dml.mathdoc.fr/item/GDZPPN002288583}
}
ECKMANN, B.; HILTON, P.J. Operators and Cooperators in Homotopy Theory.. Mathematische Annalen, Tome 141 (1960) pp. 1-21. http://gdmltest.u-ga.fr/item/GDZPPN002288583/