@article{IM2_1993_41_2_a1,
     author = {B. P. Allakhverdiev},
     title = {On~the~theory of nonselfadjoint operators of {Schr\"odinger} type with a matrix potential},
     journal = {Izvestiya. Mathematics },
     pages = {193--205},
     publisher = {mathdoc},
     volume = {41},
     number = {2},
     year = {1993},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1993_41_2_a1/}
}