@article{CM_1951__8__76_0,
     author = {Levitzki, Jakob},
     title = {On multiplicative systems},
     journal = {Compositio Mathematica},
     pages = {76--80},
     publisher = {Kraus Reprint},
     volume = {8},
     year = {1951},
     mrnumber = {33799},
     zbl = {0033.34801},
     language = {en},
     url = {http://www.numdam.org/item/CM_1951__8__76_0/}
}