1. Substitution groups of formal power series;Jennings;Can. J. Math.,1954
2. On the group of substitutions of formal power series with integer coefficients;Babenko;Izv. RAN, Ser. Mat.,2008
3. The exponent of certain finite p-groups;York;Proc. Edinb. Math. Soc.,1990
4. The Nottingham group;Camina,2000
5. Series of commutants of the Jennings group J(Z2);Bogataya;Topol. Appl.,2014