Study on the international systems of protecting plant variety 并列题名:Study on the international systems of protecting plant variety Study on the international law issues of protective jurisdiction. Study on the international law issues of protective jurisdiction 并列题名:Study on the international law issues of protective jurisdiction Studies on the international legal systems of standby letter of credit Research on the international legal system of diplomatic protection study on the integration strategy of European Union higher education 并列题名:Studies on the international legal systems of standby letter of credit Comparative study on the operational systems of the master plans in world cities