Song Sijia: Su Shi, Huang Tingjian, Mi Fei and Cai Xiang (Cai Jing's calligraphy is better than Cai Xiang's, but Cai Xiang is not Cai Jing because Cai Jing's character is bad and calligraphy pays attention to calligraphy. )
Four masters of regular script: Ou Yangxun, Yan Zhenqing, Liu Gongquan and Zhao Mengfu.
Four schools in the early Tang Dynasty: Ou Yangxun, Yu Shinan, Chu Suiliang and Xue Ji.