Magdi S. Mahmoud, Nezar M. Alyazidi and Abdalrahman M. Hassanine 2019. Modeling and Control of Underactuated Three-Dimensional Overhead Crane Systems. International Journal of Robotics and Automation Technology. 6, (Oct. 2019),   80–85. DOI:https://doi.org/10.31875/2409-9694.2019.06.10.