Rimrott, F. P. J., and B. Tabarrok. “Complementary Formulation of the Appell Equation”. Technische Mechanik - European Journal of Engineering Mechanics 16, no. 2 (October 19, 2019): 187–196. Accessed May 15, 2024. https://journals.ub.ovgu.de/index.php/techmech/article/view/1231.