R. Beals. Groups and Computation, Volume 28 von DIMACS Series in Discrete Mathematics and Theoretical Computer Science, Seite 31-54. DIMACS/AMS, (1995)
R. Beals. Groups And Computation, Volume 11 von DIMACS Series in Discrete Mathematics and Theoretical Computer Science, Seite 17-26. DIMACS/AMS, (1991)