Bondarenko, V.M. and Stepochkina, M.V. (2009) “Description of posets critical with respect to the nonnegativity of the quadratic Tits form”, Ukrains’kyi Matematychnyi Zhurnal, 61(5), pp. 611–624. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3045 (Accessed: 5 December 2025).