Liu Ti - The writing style is thin and straight, and the posture is strong and charming. "Xuanmi Pagoda", "Shence Army Stele", "Thirteen Prefaces to Orchid Pavilion", "Huiyuan Guan Bell Tower Inscription", etc.
Yan Ti - Exploring the Origin of Seal Script, the regular script is rigorous, free but not sloppy, restrained and Not clumsy, the characters are square and round, and the writing style is fat and vigorous. "Yan Qin's Ceremony Stele", "Ji Nephew's Manuscript", etc.
European style - the main script is composed of characters, changing the square to be long, so that the posture is charming, the four sides are even, the eight directions are straight, and the calligraphy is free and easy. His representative works include "Jiucheng Palace" and "Thousand-Character Essay in Running Script" etc.
Zhao Ti - the founder of Zhao Ti, famous for his romantic style. Use the pen to turn around, Qingju Huarun's "Three Gates", "Luo Shen Fu", "Tao Te Ching", etc.
But I don't know what the four masters you are talking about,
Because Tang Dynasty There are four Yu, Ou, Chu, Xue and Song, and there are four meters of Huang, Su and Cai