Melnikov, N.B., and G.V. Paradezhenko. “A Renormalized Gaussian Approximation in the Spin-Fluctuation Theory”. Numerical Methods and Programming (Vychislitel’nye Metody i Programmirovanie) 15, no. 41 (August 5, 2014): 461–475. Accessed April 30, 2024. https://en.num-meth.ru/index.php/journal/article/view/783.