Khokonov, M. Kh. «Cascade Processes of Energy Loss by Emission of Hard Photons». Journal of Experimental and Theoretical Physics, 99, 4, 2004, pàg. 690–707. DOI: 10.1134/1.1826160.. Derived from formulas sourced to I. S. Gradshteyn and I. M. Ryzhik, Table of Integrals, Series, and Products (Fizmatgiz, Moscow, 1963; Academic Press, New York, 1980).
Referred to as such in: Teichroew, D. «The Mixture of Normal Distributions with Different Variances». The Annals of Mathematical Statistics, 28, 2, 1957, pàg. 510–512. DOI: 10.1214/aoms/1177706981.