1. The theory of extensions and explicitly-solvable models`;Pavlov;Russian Math. Surveys,1987
2. Singular Perturbations of Differential Operators. Solvable Schrödinger Type Operators;Albeverio,2000
3. Solvable Models in Quantum Mechanics;Albeverio,2005
4. Self-Adjoint Extensions as a Quantization Problem;Gitman,2006