@article{GDZPPN002407604,
title = {The Hopf Property of Free Products.},
journal = {Mathematische Zeitschrift},
volume = {114},
year = {1970},
pages = {325-339},
zbl = {0204.34205},
url = {http://dml.mathdoc.fr/item/GDZPPN002407604}
}
Neumann, Hanna; Dey, I.M.S. The Hopf Property of Free Products.. Mathematische Zeitschrift, Tome 114 (1970) pp. 325-339. http://gdmltest.u-ga.fr/item/GDZPPN002407604/