Polycentric spatial structure and development strategy of urban regions in China Regional economic structure and developments strategy of the western Chinese Research on sustainable development strategy of urban construction in China Economic reform and development in rural regions in China Study on formation process and development strategy for agricultural regional cluster in China Comprehensive evaluation of ecological security and development strategy of urbanization in Xian 并列题名：Research on sustainable development strategy of urban construction in China 封面英文题名：Economic reform and development in rural regions in China 并列正题名：Regional economic structure and developments strategy of the western Chinese 并列题名：Research on the supply system and development strategy of multi-level housing in China