Faiziev, V. A., and P. K. Sahoo. “On Stability of the Cauchy Equation on Solvable Groups”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 7 (July 25, 2015): 1000–1005. Accessed December 6, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/2039.