Ashikhmin, Valeriy Nikolaevich, et al. “A Two-Level Model of Stationary Elasto-Plastic Deformation During Metal Forming Processes. Part 1. Algorithm”. Computational Continuum Mechanics, vol. 1, no. 3, Apr. 2008, pp. 15-24, https://doi.org/10.7242/1999-6691/2008.1.3.23.