@article{GDZPPN002422654,
title = {Subgroups of Finite Index in Profinite Groups.},
journal = {Mathematische Zeitschrift},
volume = {166},
year = {1979},
pages = {71-76},
zbl = {0394.20020},
url = {http://dml.mathdoc.fr/item/GDZPPN002422654}
}
Hartley, Brian. Subgroups of Finite Index in Profinite Groups.. Mathematische Zeitschrift, Tome 166 (1979) pp. 71-76. http://gdmltest.u-ga.fr/item/GDZPPN002422654/