The two documents in the background are considered the opening shots of the Cultural Revolution. The first, the "Circular of the Central Committee of the Communist Party of China on the Great Proletarian Cultural Revolution", also know as the "May 16 Notification" (五一六通知) or Circular of May 16, was the first major political declaration of the Chinese Cultural Revolution. It was issued at a May 1966 expanded session of the Politburo of the CCP. The original Chinese text can be found here. The second, the "Decision of the CC of the CCP Concerning the Great Proletarian Cultural Revolution", later known as the "Sixteen Points", was adopted on 8 August. The Chinese version is here.