@article{10_4064_sm_15_1_29_30,
     author = {J. Kope\'c and J. Musielak},
     title = {On the estimation of the norm of the n-linear symmetric operation},
     journal = {Studia Mathematica},
     pages = {29--30},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1955},
     doi = {10.4064/sm-15-1-29-30},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-15-1-29-30/}
}