What is Yan's representative work of regular script?

Yanjin Liugu is talking about Yan Zhenqing and Liu Gongquan, and Liu Gongquan is the latter. His masterpiece is the mysterious pagoda. Liu Gongquan was actually a famous calligrapher in Tang Dynasty. He is as famous as Yan Zhenqing. He studied Wang Xizhi first, and then Yan Zhenqing. After studying different calligraphers, he was able to be compatible with each other and become a whole, so he created Liu Ti. Liu Ti's font structure is rigorous, and its style is tall and straight. Liu Gongquan's handwriting is as strong as his personal character. In his official career, he dared to speak up and was praised by Tang Muzong. Therefore, Liu Gongquan's integrity and his calligraphy have always been respected by future generations.