作 者:Alexei Myasnikov, McGill University Dept. Mathematics & Statistics, Montreal, QC, Canada; Vladimir Shpilrain, City University of NewYork City College of NewYork, NewYork, NY, USA; Alexander Ushakov
作 者:Detlef Gromoll, State University of NewYork Dept. Mathematics, Stony Brook, NY, USA; Gerard Walschap, University of Oklahoma Dept. Mathematics, Norman, OK, USA