Tang Degang is a historian and biographer who specializes in oral history. In the latter half of his life, he settled in the United States and taught at Columbia University and the City University of New York. In the field of history, he put forward the "Three Gorges Theory of History", which divides the change of Chinese social system into three major stages: feudalism, imperialism, and civil rule. The book was originally titled <i>Mao Zedong's Dictatorship, 1949~1976</i>, but was renamed <i>Thirty Years of New China </i> when it was released on the mainland.
The revised edition of this book was published by *Open Magazine* in Hong Kong in 2007. The first edition was published in 1991 and was revised and reprinted twice, in 1993 and 1995. The book collects a large amount of information about the anti-rightist movement, including survey interviews with victims of the anti-rightist movement and their relatives and friends. It is a complete record of the anti-rightist movement, which comprehensively analyzes and discusses the whole process of the anti-rightist movement, as well as its ins and outs, causes and consequences. Regarding the number of "rightists," the statistics of the CCP authorities had been limited to 550,000 people. According to Ding Lyric's analysis, there were about 1.2 million people who were labeled as "rightists" in the Anti-Rightist Movement.
