1. Mackey, G.W.: Unitary representations in physics, probability and number theory. Addison Wesley, Reading (1989)
2. Wigner, E.P.: Group theory and its applications to the quantum theory of atomic spectra. Academic Press, Boston (1959)
3. Cassinelli, G., De Vito, E., Lahti, P., Levrero, A.: Rev. Math. Phys. 8, 921 (1997)
4. Mackey, G.W.: Induced representations of group and quantum mechanics. W.A. Benjamin Inc., New York (1968)
5. Mackey, G.W.: Acta. Mathematica 99, 265 (1958)