@article{SM_1991_69_1_a3,
     author = {P. A. Zalesskii},
     title = {Profinite groups acting on trees and having no free nonabelian pro-$\mathbf p$-subgroups},
     journal = {Sbornik. Mathematics},
     pages = {57--67},
     year = {1991},
     volume = {69},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_69_1_a3/}
}