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2. Spectral analysis of a q-difference operator;Bekker;J. Phys. A,2010
3. Scale-invariant self-adjoint extensions of scale-invariant symmetric operators: continuous versus discrete;Bekker;Methods Funct. Anal. Topology,2015
4. A q-difference operator with discrete and simple spectrum;Bekker;Methods Funct. Anal. Topology,2011
5. Extreme self-adjoint extensions of a semibounded q-difference operator;Bekker;Math. Nachr.,2014