@article{PIM_1974_N_S_17_31_a1,
     author = {S.C. Arora},
     title = {On certain classes of commutators},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {17 },
     publisher = {mathdoc},
     volume = {_N_S_17},
     number = {31},
     year = {1974},
     url = {http://geodesic.mathdoc.fr/item/PIM_1974_N_S_17_31_a1/}
}