@article{GDZPPN002105683,
title = {Normal-convexity and equations over groups.},
journal = {Inventiones mathematicae},
volume = {93},
year = {1988},
pages = {81-104},
zbl = {0655.20025},
url = {http://dml.mathdoc.fr/item/GDZPPN002105683}
}
Brick, Stephen G. Normal-convexity and equations over groups.. Inventiones mathematicae, Tome 93 (1988) pp. 81-104. http://gdmltest.u-ga.fr/item/GDZPPN002105683/