@article{ARM_2006__42_4_a3,
     author = {Everaert, Tomas and Gran, Marino},
     title = {Relative commutator associated with varieties of $n$-nilpotent and of $n$-solvable groups},
     journal = {Archivum mathematicum},
     pages = {387--396},
     publisher = {mathdoc},
     volume = {42},
     number = {4},
     year = {2006},
     mrnumber = {2283019},
     zbl = {1152.20030},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_2006__42_4_a3/}
}