Research on Chinas producer services import and manufacturing transformation and upgradin Research on the impact of producer services agglomeration on manufacturing servitization Study on development problems of producer services during maufacturing transformation in China Research on the key issues of Chinas industrial transformation and upgrading Research on producer services agglomeration and urban economic transformation and development Research on the evaluation and influencing factors of manufacturing industry transformation and upgrading in China Research on the path of Chinas economic transformation and upgrading Producer service import and manufacturing upgrading