@article{SM_2002_193_11_a0,
     author = {A. G. Baskakov and K. I. Chernyshov},
     title = {Spectral analysis of linear relations and degenerate operator semigroups},
     journal = {Sbornik. Mathematics},
     pages = {1573--1610},
     publisher = {mathdoc},
     volume = {193},
     number = {11},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2002_193_11_a0/}
}