“…This viewpoint has been demonstrated in many finite-and infinitedimensional cases by applying a Group Approach to Quantization developed since the original paper [8], where the quantum free Galilean particle and the harmonic oscillator were derived. Then, this algorithm has been applied to less elementary groups as those associated with relativistic particles, in particular the relativistic harmonic oscillator [9,10,11], field theories in curved space-times, non-linear σ-models, the Virasoro group and others concerning conformal symmetry and quantum gravity (see, for instance [12,13,14]). …”