Operational formulae for certain classical polynomials J. P. Singhal — 1967 Rendiconti del Seminario Matematico della Università di Padova
Multiple Series Relations Involving Hermite Polynomials J. P. Singhal; N. K. Soni — 1973 Publications de l'Institut Mathématique
On the unification of generalized Hermite and Laguerre polynomials. J. P. Singhal; C. M. Joshi — 1982 Revista Matemática Hispanoamericana