@article{05002581, title = {Heegaard gradient and virtual fibers.}, journal = {Geometry \& Topology}, volume = {5}, year = {2005}, pages = {2227-2259}, doi = {10.2140/gt.2005.9.2227}, zbl = {1100.57002}, language = {en}, url = {http://dml.mathdoc.fr/item/05002581} }
Maher, Joseph. Heegaard gradient and virtual fibers.. Geometry & Topology, Tome 5 (2005) pp. 2227-2259. doi : 10.2140/gt.2005.9.2227. http://gdmltest.u-ga.fr/item/05002581/