Robuta

https://functions.wolfram.com/HypergeometricFunctions/AppellF1/06/01/05/ Appell function F1: Series representations (subsection 06/01/05) appell function series representations subsection https://research.ajman.ac.ae/en/publications/a-reduction-formula-for-the-appell-series-f3-in-two-variables/ A reduction formula for the Appell series F3 in two variables - Ajman University reduction formula appell series in two ajman university variables