@article{GDZPPN002428083,
title = {Surfaces in Three-Manifolds and Non-Singular Equations in Groups.},
journal = {Mathematische Zeitschrift},
volume = {183},
year = {1983},
pages = {1-18},
zbl = {0496.57006},
url = {http://dml.mathdoc.fr/item/GDZPPN002428083}
}
Stallings, John R. Surfaces in Three-Manifolds and Non-Singular Equations in Groups.. Mathematische Zeitschrift, Tome 183 (1983) pp. 1-18. http://gdmltest.u-ga.fr/item/GDZPPN002428083/