@article{GDZPPN002056402, title = {On mappings into group-like spaces.}, journal = {Commentarii mathematici Helvetici}, volume = {28}, year = {1954}, pages = {320-328}, zbl = {0058.16801}, url = {http://dml.mathdoc.fr/item/GDZPPN002056402} }
Whitehead, George W. On mappings into group-like spaces.. Commentarii mathematici Helvetici, Tome 28 (1954) pp. 320-328. http://gdmltest.u-ga.fr/item/GDZPPN002056402/