Zubkova, E.I. and Rofe-Beketov, F.S. (2009) “Inverse scattering problem on the axis for the triangular $2\times 2$ matrix potential with a virtual level”, Methods of Functional Analysis and Topology, 15(4), pp. 301–321. Available at: https://zen.imath.kiev.ua/index.php/mfat/article/view/426 (Accessed: 16 December 2025).