@article{IM2_1969_3_1_a4,
     author = {L. A. Sakhnovich},
     title = {Nonunitary operators with absolutely continuous spectrum},
     journal = {Izvestiya. Mathematics },
     pages = {51--63},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1969_3_1_a4/}
}