@article{MAN_1965__160_161290,
     author = {M.I. KNOPP and J. LEHNER and M. NEWMAN},
     title = {Subgroups of {F-groups.}},
     journal = {Mathematische Annalen},
     pages = {312--318},
     publisher = {mathdoc},
     volume = {160},
     year = {1965},
     zbl = {0132.01301},
     url = {http://geodesic.mathdoc.fr/item/MAN_1965__160_161290/}
}