@article{FPM_2001_7_2_a4,
     author = {S. V. Zelenov},
     title = {Zelmanowitz density theorem for rings graded by semigroup},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {373--385},
     publisher = {mathdoc},
     volume = {7},
     number = {2},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_2001_7_2_a4/}
}