Ali, M., C. Lam, K. Ch’ng, K. Sundaraj, and W.-H. Tan. “Design and Development of Path Planning Techniques for a Tennis Ball Retriever Robot”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC), vol. 10, no. 1-15, May 2018, pp. 59-65, https://jtec.utem.edu.my/jtec/article/view/4047.