Jung Chang and Jon Halliday’s Mao: The Unknown Story (London, 2006) provides a great deal of new detail, and assesses Mao in ultimately negative terms. Philip Short, Mao: A Life (London, 2001), and Alexander Pantsov and Steven Levine, Mao: The Real Story (New York, 2012), suggest that Mao both made important contributions to the revolution and committed terrible crimes. A fine guide to the controversies over Mao is Timothy Cheek, ed., A Critical Introduction to Mao (Cambridge, 2010).