@article{IM2_1996_60_2_a3, author = {V. V. Nikulin}, title = {Reflection groups in {Lobachevskii} spaces and the denominator identity for {Lorentzian} {Kac{\textendash}Moody} algebras}, journal = {Izvestiya. Mathematics}, pages = {305--334}, year = {1996}, volume = {60}, number = {2}, language = {en}, url = {http://geodesic.mathdoc.fr/item/IM2_1996_60_2_a3/} }