Pham, Khoi. “Measurement -Based Electrical Parameters of Power Transformers for Frequency Response Analysis Interpretation - Part I: Core Analysis”. VNUHCM Journal of Science and Technology Development 20, no. K3 (June 30, 2017): 5-10. Accessed August 31, 2025. http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/1074.