@article{01423415,
title = {Doubles of groups and hyperbolic LERF 3-manifolds.},
journal = {Annals of Mathematics. Second Series},
volume = {150},
year = {1999},
pages = {775-806},
doi = {10.2307/121056},
zbl = {0944.20023},
language = {en},
url = {http://dml.mathdoc.fr/item/01423415}
}
Gitik, Rita. Doubles of groups and hyperbolic LERF 3-manifolds.. Annals of Mathematics. Second Series, Tome 150 (1999) pp. 775-806. doi : 10.2307/121056. http://gdmltest.u-ga.fr/item/01423415/