Limit Theorems for Random Walks on Discrete Semigroups Related to Nonhomogeneous Trees and Chebyshev Polynomials. P.M. Soardi Mathematische Zeitschrift
Recurrence and transience of the edge graph of a tiling of the euclidean plane. P.M. Soardi — 1990 Mathematische Annalen
On Multiresolution Analysis of Multiplicity d. P.M. Soardi; L. De Michele — 1997 Monatshefte für Mathematik