Khalina, K. S. (2012) “Boundary controllability problems for the equation of oscillation of an inhomogeneous string on a semiaxis”, Ukrains’kyi Matematychnyi Zhurnal, 64(4), pp. 525-541. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2593 (Accessed: 28April2024).