Progress of Theoretical Physics SupplementSome Mathematical Problems in Quantum MechanicsTosio KatoPublished Jan 1, 1967• 35 citationsPublisherAbstractTosio Kato; Some Mathematical Problems in Quantum Mechanics, Progress of Theoretical Physics Supplement, Volume 40, 1 February 1967, Pages 3–19, https://doi.orgDOI10.1143/ptps.40.3