@article{RM_1977_32_5_a1,
     author = {\`E. R. Tsekanovskii and Yu. L. Shmul'yan},
     title = {The theory of bi-extensions of operators on rigged {Hilbert} spaces. {Unbounded} operator colligations and characteristic functions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {73--131},
     publisher = {mathdoc},
     volume = {32},
     number = {5},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1977_32_5_a1/}
}