1. This definition was first given by G.ROEPSTORFF, Comm. Math. Phys. 9, 315 (1968).
2. A complete blibliography on the introduction and properties of coherent states in quantum mechanics can be found in J.KLAUDER and E.C.G.SUDARSHAN “Fundamentals of Quantum Optics” W.A.Benjamin (1968) Chapter 7.
3. V.BARGMANN, P.BUTERA, L.GIRARDELLO and J.R.KLAUDER, Reports on Math. Phys. 2, 221 (1971).
4. V.BARGMANN, Comm. Pure Appl. Math. 14, 185 (1961).
5. Reference (2), Chapter 8.4.