Tsuboi, Yuta, Yuya Unno, Hisashi Kashima, and Naoaki Okazaki. “Fast Newton-CG Method for Batch Learning of Conditional Random Fields”. Proceedings of the AAAI Conference on Artificial Intelligence 25, no. 1 (August 4, 2011): 489–494. Accessed May 7, 2026. https://ojs.aaai.org/index.php/AAAI/article/view/7894.