@article{MZ_1956__66_169618,
     author = {A. Karrass and D. Solitar},
     title = {Some {Remarks} on the {Infinite} {Symmetric} {Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {64--69},
     publisher = {mathdoc},
     volume = {66},
     year = {1956},
     zbl = {0071.02401},
     url = {http://geodesic.mathdoc.fr/item/MZ_1956__66_169618/}
}