W. Herfort, P.A. Zalesskii:
"Virtually Free Pro-p Groups";
Trabalhos de Matematica, Universidade de Brasilia, Departamento de Matematica (invited), 329 (2003), 1 - 52.
Virtually free pro-p groups act on a pro-p tree with finite vertex stabilizers. The result extends earlier work of the same authors since G is not assumed to be finitely generated.