Ge, Xin-Sheng, et al. “Symbolic Linearization of Differential Algebraic Equations Based on Cartesian Coordinates”. Technische Mechanik - European Journal of Engineering Mechanics, vol. 25, no. 3-4, Aug. 2019, pp. 230-4, https://journals.ub.ovgu.de/index.php/techmech/article/view/908.