Xu, Zenglin, Rong Jin, Bin Shen, and Shenghuo Zhu. 2015. “Nystrom Approximation for Sparse Kernel Methods: Theoretical Analysis and Empirical Evaluation”. Proceedings of the AAAI Conference on Artificial Intelligence 29 (1). https://doi.org/10.1609/aaai.v29i1.9626.