Zhigang, F. et al. 2025. The transfer characteristics of the world technological activities center countries: The perspective of patent big data analysis: 世界技术活动中心国家转移特征研究—基于专利大数据分析视角. Studies in Science of Science. 43, 7 (Jul. 2025), 502–515. DOI:https://doi.org/10.65967/siss.v43i7.93.