Determination of an exact solution to the integral Gelfand - Levitan - Marchenko equation for the Sturm - Liouville operators with the step-type potential. НК [Internet]. 2003 Mar. 29 [cited 2026 Jan. 22];6(1):74-82. Available from: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/250