Xiaoping, Bai, et al. “A Sliding-Mode Variable-Structure Controller Based on Exact Feedback Linearization for Automatic Navigation System”. International Journal of Agricultural and Biological Engineering, vol. 9, no. 5, Sept. 2016, pp. 158-65, https://ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/1830.