1. P. Delerue, Sur le calcul symbolic a` n variables et fonctions hyperbesséliennes (II). Annales Soc. Sci. Bruxelle Ser. 1, No 3 (1953), 229–274.
2. O. I. Marichev, Method of Calculation of Integrals of Special Functions (in Russian). Nauka i Technika, Minsk (1978).
3. I. Dimovski, Operational calculus for a class of differential operators. Compt. Rend. Acad. Bulg. Sci. 19, No 12 (1966), 1111–1114.
4. M. Kljuchantzev, On the construction of r-even solutions of singular differential equations. Dokladi AN SSR 224, No 5 (1975), 1000–1008 (In Russian).
5. M. Kljuchantzev, An introduction to the theory of (ν1, …, νr−1)-transforms. Mat. Sbornik 132, No 2 (1987), 167–181 (In Russian).