%0 Journal Article %A V. F. Veselov %A S. N. Naboko %T The determinant of the characteristic function and the singular spectrum of a nonselfadjoint operator %J Sbornik. Mathematics %D 1987 %P 21-41 %V 57 %N 1 %U http://geodesic.mathdoc.fr/item/SM_1987_57_1_a1/ %G en %F SM_1987_57_1_a1