@article{GDZPPN002046628,
title = {On endomorphisms and quasi-endomorphisms of torsionfree groups},
journal = {Beitr\"age zur Algebra und Geometrie = Contributions to algebra and geometry},
volume = {4},
year = {1975},
pages = {15-22},
zbl = {0336.20039},
url = {http://dml.mathdoc.fr/item/GDZPPN002046628}
}
LEEÜWEN, L.C.A. van. On endomorphisms and quasi-endomorphisms of torsionfree groups. Beiträge zur Algebra und Geometrie = Contributions to algebra and geometry, Tome 4 (1975) pp. 15-22. http://gdmltest.u-ga.fr/item/GDZPPN002046628/