1. R. Camina, Subgroups of the Nottingham group, Ph.D. thesis, London, 1996.
2. Subgroups of the Nottingham group;Camina;J. Algebra,1997
3. I. Fesenko, On just infinite pro-p groups and arithmetically profinite extensions of local fields, preprint 99, Algebraic Number Theory Archive, (, http://www.math.uiuc.edu/Algebraic-Number-Theory, ), 1998.
4. Substitution groups of formal power series;Jennings;Canad. J. Math.,1954
5. The group of formal power series under substitution;Johnson;J. Austral. Math. Soc.,1988