Dr. Yiguo Zhang, senior consultant of Hong Kong Poly Auction, and director of Chinese painting department of Beijing Poly Auction. He is an internationally recognized expert in Chinese art. He is the author of many books, including Orthodoxy or Wild Way: Wang Duo and His Contemporaries (Beijing: Culture and Art Publishing, 2010). His exhibition: Brushed Voices: Calligraphy in Contemporary China (Columbia University, 1998), received very favorable reviews from New York Time and the catalogue was a "best seller" in the field. He served as a research fellow at the Boston Museum of Fine Arts, and the Metropolitan of Art from 1998 through 2004.