@article{SM_2006_197_7_a1,
     author = {M. F. Gorodnii and A. V. Chaikovskii},
     title = {A~generalization of the concept of sectorial operator},
     journal = {Sbornik. Mathematics},
     pages = {977--995},
     year = {2006},
     volume = {197},
     number = {7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2006_197_7_a1/}
}