@article{DAN_1961_139_1_a11,
     author = {\`E. R. Tsekanovskii},
     title = {The real and imaginary parts of an unbounded operator},
     journal = {Doklady Akademii Nauk},
     pages = {48--51},
     publisher = {mathdoc},
     volume = {139},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_1_a11/}
}