@article{MZ_1964__85_170310,
     author = {Frank Levin},
     title = {On some varieties of soluble.},
     journal = {Mathematische Zeitschrift},
     pages = {369--372},
     publisher = {mathdoc},
     volume = {85},
     year = {1964},
     zbl = {0122.03002},
     url = {http://geodesic.mathdoc.fr/item/MZ_1964__85_170310/}
}