@article{MS2_1986__59_166986,
     author = {Efraim P. Armendariz},
     title = {On infinite periodic rings.},
     journal = {Mathematica Scandinavica},
     pages = {5--8},
     year = {1986},
     volume = {59},
     zbl = {0613.16009},
     url = {http://geodesic.mathdoc.fr/item/MS2_1986__59_166986/}
}