Pochynaiko, M. D., and Yu. M. Sidorenko. 2006. “Construction of Scattering Operators by the Method of Binary Darboux Transformations”. Ukrains’kyi Matematychnyi Zhurnal 58 (8), 1097–1115. https://umj.imath.kiev.ua/index.php/umj/article/view/3516.