@article{CMFD_2021_67_2_a5,
     author = {E. V. Kissin and V. S. Shulman},
     title = {On representations of groups and algebras in spaces with indefinite metric},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {295--315},
     year = {2021},
     volume = {67},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2021_67_2_a5/}
}