1. The virtual Haken conjecture, with an appendix by Agol, I., D. Groves, J. Mannings;Agol, Ian;Doc. Math.,2013
2. A geometric invariant of discrete groups;Bieri, Robert;Invent. Math.,1987
3. [3] Eisenbud, David Commutative Algebra. With a View Towards Algebraic Geometry, Graduate Texts in Mathematics, 150, Springer, 1995
4. On embedding of group rings of residually torsion-free nilpotent groups into division rings;Eizenbud, A.;Trans. Am. Math. Soc.,1987
5. A survey of twisted Alexander polynomials;Friedl, Stefan;The Mathematics of Knots: Theory and Application,2008