However, they all belong to periodical collections, that is, the relevant copyrights are handled by periodicals that collect and replace papers. In fact, there are still some foreign papers.

China Knowledge Network refers to China's national knowledge infrastructure, which is a knowledge informatization construction project initiated by Tsinghua University and Tsinghua University with the support of the Ministry of Education, Publicity Department of the Communist Party of China, Ministry of Science and Technology, State Administration of Press, Publication, Radio, Film and Television, and State Planning Commission, aiming at realizing the dissemination, enjoyment and value-added utilization of knowledge resources in the whole society. Established in June 1999.