1. Subgroups and subrings of profinite rings;Abercrombie;Math. Proc. Cambridge Philos. Soc.,1994
2. Hausdorff dimension, pro-p groups, and Kac–Moody algebras;Barnea;Trans. Amer. Math. Soc.,1997
3. Products of Automata;Gécseg,1986
4. Abstract theory of automata;Gluškov;Uspekhi Mat. Nauk,1961
5. On the Milnor problem of group growth;Grigorchuk;Dokl. Akad. Nauk SSSR,1983