What are Li Zhimin’s contributions to the history of Chinese calligraphy?

Li Zhimin (1925-1994), a senior professor at Peking University, a leading legal scholar, the first president of the Yanyuan Calligraphy and Painting Association of Peking University (the predecessor of the Peking University Calligraphy and Painting Association), a director of the Chinese Calligraphers Association and the Art Committee of the Chinese Calligraphers Association Deputy director of the Beijing Calligraphers Association, first vice president of the Beijing Calligraphers Association and director of the evaluation committee. In his early years, he studied at Wuchang Art College, and later taught at Peking University. He is proficient in four foreign languages: English, French, German and Russian. He also has a profound foundation in traditional Chinese studies. He is good at poetry and painting, and is good at both seal and regular script. He is especially good at Wei stele and Kuangcao. His Kuangcao has filled a gap in the history of Kuangcao in China in the 20th century. At the same time, he has made great contributions to the study of calligraphy theory. He is the author of Sanchuntang's "Calligraphy Theory - Sanchuntang Study Notes" (Peking University Press, 1992 edition) and "Cao Lun - Sanchuntang Kuangcao" (Peking University Press, 2014 edition). He is a master of contemporary calligraphy in my country and the pioneer of introducing stele into grass. Together with Shen Yinmo, he is known as "the two giants in the history of Peking University calligraphy", and together with Lin Sanzhi, he is known as "Southern Lin and Northern Li".