@article{SM_1974_24_1_a5,
     author = {A. G. Brusentsev and F. S. Rofe-Beketov},
     title = {Selfadjointness conditions for strongly elliptic systems of arbitrary order},
     journal = {Sbornik. Mathematics},
     pages = {103--126},
     publisher = {mathdoc},
     volume = {24},
     number = {1},
     year = {1974},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_24_1_a5/}
}