@article{SF_1989__39_2_134989,
     author = {A.B. Engel and L. Makar-Limanov},
     title = {On groups rings which are not {Ore} domains.},
     journal = {Semigroup forum},
     pages = {249--254},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1989},
     zbl = {0669.16008},
     url = {http://geodesic.mathdoc.fr/item/SF_1989__39_2_134989/}
}