Research on the system of statutory license in copyright 并列题名:Research on the system of statutory license in copyright Research on the regulation of network audiovisual copyright Research on the system of social credit system in Chian Research on the legal status of derivative works in copyright law Research on the system of social service for old people in cities Research on the expansion and limitation of objects of copyright 并列题名:Research on the regulation of network audiovisual copyright Research on legal system of digital publishing copyright protection 并列题名:Research on the legal status of derivative works in copyright law