@article{MZM_2004_76_5_a12,
     author = {M. V. Feigin},
     title = {Quasi-Invariants of {Dihedral} {Systems}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {776--791},
     year = {2004},
     volume = {76},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2004_76_5_a12/}
}