@article{CMH_1952__26_139031,
     author = {H. Meier-Wunderli},
     title = {Note on a basis of {P.} hall for the higher commutators in free groups.},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--5},
     publisher = {mathdoc},
     volume = {26},
     year = {1952},
     zbl = {0046.02201},
     url = {http://geodesic.mathdoc.fr/item/CMH_1952__26_139031/}
}