@article{IM2_1973_7_3_a3,
     author = {V. I. Liberzon and V. S. Shul'man},
     title = {Nondegenerate operator algebras in spaces with an indefinite metric},
     journal = {Izvestiya. Mathematics },
     pages = {529--534},
     publisher = {mathdoc},
     volume = {7},
     number = {3},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1973_7_3_a3/}
}