1. The history of Blissard’s symbolic method with a sketch of its inventor’s life;Bell;Amer. Math. Monthly,1938
2. Postulational bases for the umbral calculus;Bell;Amer. J. Math.,1940
3. Enumerazione binomiale e processi stocastici di Poisson composti;Cerasoli;Bollettino U.M.I.-A,1979
4. A selected survey of umbral calculus;Di Bucchianico;Electron. J. Combin.,1995
5. Umbral nature of the Poisson random variables;Di Nardo,2001