1. Bachman D, Schleimer S, Sedgwick E. Sweepouts of amalgamated 3-manifolds. Algebr Geom Topol, 2006, 6: 171–194
2. Hempel J. 3-Manifolds. Annals of Mathematics Studies. Princeton: Princeton University Press, 1976
3. Jaco W. Three-manifolds with fundamental group a free product. Bull Amer Math Soc, 1969, 75: 972–977
4. Jaco W. Lectures on Three-Manifold Topology. CBMS Regional Conference Series in Mathematics, No. 43. Providence: Amer Math Soc, 1980
5. Jaco W. Adding a 2-handle to a 3-manifold: An application to property R. Proc Amer Math Soc, 1984, 92: 288–292