1. B. A. Ditkin, “Some approximate formulae for evaluating triple integrals,” Dokl. Akad. Nauk SSSR, v. 62, 1948, p. 445-7.
2. C. Finden, Spherical integration, Dissertation submitted for the Diploma in Numerical Analysis and Automatic Computing, University of Cambridge, 1961.
3. Numerical evaluation of multiple integrals. II;Hammer, Preston C.;Math. Tables Aids Comput.,1958
4. International Series in Natural Philosophy, Vol. 91;Heine, Volker,1977
5. D. G. Kendall, “Gaussian integration on the sphere,” Unpublished Report to the Atlas Computer Laboratory, 1962.