@article{SM_1990_66_1_a11,
     author = {R. I. Grigorchuk},
     title = {On the {Hilbert{\textendash}Poincar\'e} series of graded algebras associated with groups},
     journal = {Sbornik. Mathematics},
     pages = {211--229},
     year = {1990},
     volume = {66},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1990_66_1_a11/}
}