Bradley, Sean. “Cultivating the Elixir Field with Sinmoo Hapkido’s Danjun Breathing”. Revista de Artes Marciales Asiáticas 1, no. 4 (July 17, 2012): 76–89. Accessed May 11, 2025. https://revistas.unileon.es/index.php/artesmarciales/article/view/271.