What are the three kinds of running script copybooks?

The three major running scripts refer to Preface to Lanting, Ji Ming Manuscript and Huangzhou Cold Food Poetry.

Throughout the development history of China's running script 1800 years, three outstanding calligraphers have set up immortal monuments, namely Wang Xizhi, Yan Zhenqing and Su Shi. The representative works of running script include Preface to the Lanting Pavilion, Nephew's Book and Huangzhou Cold Food Poetry, which are known as "the three major running scripts in the world".