Filippov, S. B., et al. “Buckling Analysis of Axially Compressed Square Elastic Tubes With Weakly Supported Edges”. Technische Mechanik - European Journal of Engineering Mechanics, vol. 20, no. 1, Sept. 2019, pp. 13-20, https://journals.ub.ovgu.de/index.php/techmech/article/view/1067.