Bondarenko, V.V., Bondarenko, V.M. and Pereguda, Y.N. (2012) “Local deformations of positive-definite quadratic forms”, Ukrains’kyi Matematychnyi Zhurnal, 64(7), pp. 892–907. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2626 (Accessed: 6 December 2025).