1. Dehn M. Über unendliche diskontinuierliche gruppen. Mathematische Annalen, 1911, 71: 116–144.
2. Adian S. The unsolvability of certain algorithmic problems in the theory of groups. Trudy Moskov. Math. Obshch, 1957, 6: 231–298.
3. Babai L, Szemerédi E. On the complexity of matrix group problems i. In Proc. IEEE Annual Symposium on Foundations of Computer Science (FOCS), West Palm Beach, Florida, USA, October 24–26, 1984, pp.229–240.
4. Köbler J, Schöning U, Torán J. The Graph Isomorphism Problem: Its Structural Complexity. Boston: Birkhauser, 1993.
5. Chattopadhyay A, Torán J, Wagner F. Graph isomorphism is not AC 0 reducible to group isomorphism. In Proc. Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2010), Chennai, India, Dec. 15–18, 2010, pp.317–326.