1. F. Calogebo:Motion of poles and zeros of special solutions of partial differential equations, and related «solvable » many-body problems (submitted toNuovo Cimento B).
2. For the classical polynomials we use the motion otA. Erdélyi (Editor):Higher Transcendental Functions, Vol.2 (New York, N. Y., 1953).
3. S. Szegö:Orthogonal Polynomials, Vol.23, subsect. 6.7 (New York, N. Y., 1939).
4. See eqs. 10.13 (2) and 10.13 (3) of ref. (2).
5. See for instance eqs. 10.8 (16) of ref. (2).