1. T. Regge, “Algebraic topology methods in the theory of Feynman relativistic amplitudes,” in Battelle Rencontres: 1967 Lectures in Mathematics and Physics, Ed. by C. M. DeWitt and J. A. Wheeler (Benjamin, New York, 1968).
2. A. M. Mathai and R. K. Saxena, Generalized Hypergeometric Functions with Applications in Statistics and Physical Sciences (Springer-Verlag, Berlin, 1973).
3. H. Exton, Multiple Hypergeometric Functions and Application (Willey, New York, 1976).
4. W. Miller, Symmetry and Separation of Variables (Addison-Wesley, Reading, Mass., 1977; Mir, Moscow, 1981).
5. S. Yu. Slavyanov and W. Lay, Special Functions: A Unified Theory Based on Singularities (Oxford Univ. Press, Oxford, 2000).