Fushchich , V. I., V. A. Tychinin, and N. I. Serov. “Formula for Multiplication of Solutions of the Cortevegs—de Fries Equations”. Ukrains’kyi Matematychnyi Zhurnal 44, no. 5 (May 26, 1992): 716–719. Accessed December 6, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/7972.