@article{MZ_1964__84_170246,
     author = {Carlton Christensen},
     title = {Complementation in groups.},
     journal = {Mathematische Zeitschrift},
     pages = {52--69},
     publisher = {mathdoc},
     volume = {84},
     year = {1964},
     zbl = {0134.02703},
     url = {http://geodesic.mathdoc.fr/item/MZ_1964__84_170246/}
}