Wells, Marnix, and Stanley E. Henning. “Boxer Zhang Songxi and the Origins of the Internal-External School Concept”. Revista de Artes Marciales Asiáticas 6, no. 2 (May 27, 2012): 19–28. Accessed October 4, 2022. https://revpubli.unileon.es/ojs/index.php/artesmarciales/article/view/5.