In this work, we prove that every closed, orientable 3-manifold M3 which is a two-fold covering of S3 branched over a link, has type six.
@article{urn:eudml:doc:44291, title = {Two-fold branched coverings of S3 have type six.}, journal = {Revista Matem\'atica de la Universidad Complutense de Madrid}, volume = {5}, year = {1992}, pages = {235-254}, zbl = {0781.57010}, mrnumber = {MR1195082}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:44291} }
Casali, Maria Rita. Two-fold branched coverings of S3 have type six.. Revista Matemática de la Universidad Complutense de Madrid, Tome 5 (1992) pp. 235-254. http://gdmltest.u-ga.fr/item/urn:eudml:doc:44291/