Predicting willingness to donate blood based on machine learning: two blood donor recruitments during COVID-19 outbreaks oleh Hong-yun Wu, Zheng-gang Li, Xin-kai Sun, Wei-min Bai, An-di Wang, Yu-chi Ma, Ren-hua Diao, Eng-yong Fan, Fang Zhao, Yun-qi Liu, Yi-zhou Hong, Ming-hua Guo, Hui Xue, Wen-biao Liang