Bertram, A. “Sayir, M. B.; Dual, J.; Kaufmann S.: Ingenieurmechanik 1 - 3”. Technische Mechanik - European Journal of Engineering Mechanics, vol. 31, no. 2, July 2019, p. 171, https://journals.ub.ovgu.de/index.php/techmech/article/view/768.