On the problem of convergence of a bounded-below sequence of symmetric forms for the Schrödinger operators Yu. Semenov — 1979 Studia Mathematica
Essential self-adjointness of many-particle hamiltonian operators of Schrödinger type with singular two-particle potentials V. F. Kovalenko; Yu. A. Semenov — 1977 Annales de l'I.H.P. Physique théorique