Un algorithme pour calculer l'invariant de Walker Christine Lescop (1990) Bulletin de la Société Mathématique de France
Universal manifold pairings and positivity. Freedman, Michael H., Kitaev, Alexei, Nayak, Chetan, Slingerland, Johannes K., Walker, Kevin, Wang, Zhenghan (2005) Geometry & Topology
Upper semicontinuous decompositions of convex metric spaces Stephen Rodabaugh (1980) Fundamenta Mathematicae