@article{GDZPPN002356570,
title = {Nielsen methods in groups with a length function.},
journal = {Mathematica Scandinavica},
volume = {48},
year = {1981},
pages = {153-164},
zbl = {0463.20023},
url = {http://dml.mathdoc.fr/item/GDZPPN002356570}
}
Hoare, A.H.M. Nielsen methods in groups with a length function.. Mathematica Scandinavica, Tome 48 (1981) pp. 153-164. http://gdmltest.u-ga.fr/item/GDZPPN002356570/