F. Zhigang, Z. Zhiqiang, and L. Hao, “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”, siss, vol. 43, no. 7, pp. 502–515, Jul. 2025, Accessed: Jan. 23, 2026. [Online]. Available: https://casscience.cn/siss/article/view/93