Progress of Theoretical PhysicsOperator Formalism as a Quantized Version of Analogue ModelTamiaki YoneyaPublished Apr 1, 1971• 1 citationPublisherAbstractTamiaki Yoneya; Operator Formalism as a Quantized Version of Analogue Model, Progress of Theoretical Physics, Volume 45, Issue 4, 1 April 1971, Pages 1346–1347,DOI10.1143/ptp.45.1346