@article{ZNSL_2015_437_a0,
     author = {V. Arzumanian and S. Grigoryan},
     title = {Group-graded systems and algebras},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {5--14},
     publisher = {mathdoc},
     volume = {437},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2015_437_a0/}
}