Absolute continuity of the spectrum of a Schrödinger operator with a potential which is periodic in some directions and decays in others. Filonov, N.; Klopp, F. — 2004 Documenta Mathematica
Absence of the singular continuous component in the spectrum of analytic direct integrals. Filonov, N.; Sobolev, A.V. — 2004 Zapiski Nauchnykh Seminarov POMI