@article{GDZPPN002432013,
title = {Products of Conjugacy Classes in a Free Group: a Counterexample.},
journal = {Mathematische Zeitschrift},
volume = {192},
year = {1986},
pages = {167-182},
zbl = {0601.20034},
url = {http://dml.mathdoc.fr/item/GDZPPN002432013}
}
Gersten, S.M. Products of Conjugacy Classes in a Free Group: a Counterexample.. Mathematische Zeitschrift, Tome 192 (1986) pp. 167-182. http://gdmltest.u-ga.fr/item/GDZPPN002432013/