Dang, H. A., & Rogers, F. H. (2008). The growing phenomenon of private tutoring: Does it deepen human capital, widen inequalities, or waste resources?. The World Bank Research Observer, 23(2), 161-200.[2] Wright, E., Lee, M., & Feng, S. (2018). Shadowing the International Baccalaureate: private supplementary tutoring for the diploma programme in China. Educational Research for Policy and Practice, 17, 127-43.[3] Mark Bray, Liu Junyan(2015).Conducting Research into Private Supplementary Tutoring: Methods and Approaches. Peking University Education Review (03),2-16+187.[4] Chen Hua.(2022).On Interest Structure and Governance Mechanism of Out-of-school Training Education. Global Educaiton(12),32-45.[5] Zhang, W., & Yamato, Y. (2018). Shadow education in East Asia: Entrenched but evolving private supplementary tutoring. In Routledge international handbook of schools and schooling in Asia (pp. 323-332). Routledge.[6] Bray, M. (2010). Researching shadow education: Methodological challenges and directions. Asia Pacific Education Review, 11, 3-13.[7] Yu, H., & Ding, X. (2011). How to get out of the prisoners’ dilemma: Educational resource allocation and private tutoring. Frontiers of Education in China, 6, 279-92.[8] Manzon, M., & Areepattamannil, S. (2014). Shadow education s: Mapping the global discourse. Asia Pacific Journal of Education, 34(4), 389-402.[9] Bray, M., & Lykins, C. (2012). Shadow education: Private supplementary tutoring and its implications for policy makers in Asia (No. 9). Asian Development Bank.[10]Zhang, W. (2020). Shadow education in the service of tiger parenting: Strategies used by middle-class families in China. European Journal of Education, 55(3), 388-404.