1. L. Babai and Á. Seress, On the diameter of permutation groups, European J. Combin. 13 (1992), 231--243.
2. H. Bass and A. Lubotzky, Nonarithmetic superrigid groups: Counterexamples to Platonov's conjecture, Ann. of Math. (2) 151 (2000), 1151--1173.
3. J. D. Dixon and B. Mortimer, Permutation Groups, Grad. Texts in Math. 163, Springer, New York, 1996.
4. R. I. Grigorchuk, On the Milnor problem of group growth (in Russian), Dokl. Akad. Nauk SSSR 271, no. 1 (1983), 30--33.
5. English translation in Soviet Math. Dokl. 28, no. 1 (1983), 23--26.