@article{10_1017_S0017089500001208,
     author = {Leavitt, W. G. and Watters, J. F.},
     title = {On smallest radical and semi-simple classes},
     journal = {Glasgow mathematical journal},
     pages = {98--104},
     year = {1971},
     volume = {12},
     number = {2},
     doi = {10.1017/S0017089500001208},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500001208/}
}