@article{PIM_1980_N_S_27_41_a21,
     author = {Sava Krsti\'c},
     title = {On {Symmetric} {Words} {In} {Nilpotent} {Groups}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {139 },
     publisher = {mathdoc},
     volume = {_N_S_27},
     number = {41},
     year = {1980},
     url = {http://geodesic.mathdoc.fr/item/PIM_1980_N_S_27_41_a21/}
}