@article{MZ_1983__184_173343,
     author = {Zbigniew S. Marciniak},
     title = {Idempotents in {Group} {Rings.}},
     journal = {Mathematische Zeitschrift},
     pages = {19--28},
     publisher = {mathdoc},
     volume = {184},
     year = {1983},
     zbl = {0513.16009},
     url = {http://geodesic.mathdoc.fr/item/MZ_1983__184_173343/}
}