Researcher Guo Biqiang introduces the bid process of the files on the Nanjing Massacre at the Second Historical Archives of China in Nanjing, capital of east China's Jiangsu Province, June 12, 2014. China is applying to UNESCO to list 11 sets of documents relating to the 1937 Nanjing Massacre on the Memory of the World Register. The documents, which include diaries, films, photographs and testimonies, depict the brutality of Japanese invaders in the massacre. [Xinhua]