Karkauskas, R. and Popov, M. 2011. Composition feature of the element tangent stiffness matrix of geometrically nonlinear 2D frame structures. Mokslas – Lietuvos ateitis / Science – Future of Lithuania. 1, 5 (Apr. 2011), 45-49. DOI:https://doi.org/10.3846/mla.2009.5.09.