Learning calligraphy requires knowing which three calligraphers Li San refers to.

Li Beihai, a famous calligrapher in Tang Dynasty, wrote "Lushan Temple Monument", which is his masterpiece.

Li Shimin, Emperor Taizong of Tang Dynasty, was also highly accomplished in calligraphy, and his masterpiece was The Name of Hot Springs.

Li Bai, a poet in the Tang Dynasty, is also good at calligraphy, and there are not many surviving works.

Ancient Chinese characters are a good book.

We really can't think of any other Li calligraphy in history.