1. A review of the decomposition method in applied mathematics;Adomian;J. Math. Anal. Appl.,1988
2. Polyharmonic Functions;Aronszajn,1983
3. On the operator Δr2+μ(∂/∂r)r+λ;Baouendi;J. Differential Equations,1974
4. Higher Transcendental Functions, Vol. 2;Bateman,1953
5. Uravneniya Matematicheskoy Fiziki;Bitsadze,1982