Hermann, M., et al. “Theoretical and Numerical Studies of the Shell Equations of Bauer, Reiss and Keller, Part I: Mathematical Theory”. Technische Mechanik - European Journal of Engineering Mechanics, vol. 19, no. 1, Oct. 2019, pp. 53-62, https://journals.ub.ovgu.de/index.php/techmech/article/view/1113.