1. Transverse cellular mappings of polyhedra;Akin;Trans. A.M.S.,1972
2. Free groups and handle bodies;Andrews;Proc. A.M.S.,1965
3. Extended Nielsen operations in free groups;Andrews;Amer. Math. Month.,1966
4. Heegaard genus of close orientable Seifert 3-manifolds;Boileau;Invent. Math.,1984
5. Elementaroperationen bei Gruppenpräsentationen und Heegaard-Diagramme mit Singularitäten;Christ,1984