@article{AA_1991_3_3_a5,
     author = {Manfred M\"oller},
     title = {Isometric and contractive operators in {Kreǐn} spaces},
     journal = {Algebra i analiz},
     pages = {110--126},
     year = {1991},
     volume = {3},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AA_1991_3_3_a5/}
}