Tong, Zhengyan, Xuanhong Chen, Bingbing Ni, and Xiaohang Wang. 2021. “Sketch Generation With Drawing Process Guided by Vector Flow and Grayscale”. Proceedings of the AAAI Conference on Artificial Intelligence 35 (1):609-16. https://ojs.aaai.org/index.php/AAAI/article/view/16140.