^Alex Kozma (2013). Warrior Guards the Mountain: The Internal Martial Traditions of China, Japan, and South East Asia. Singing Dragon. ISBN978-18-481-9124-2.
^Gao Yisheng (2013). Liu Fengcai (ed.). The Cheng School Gao Style Baguazhang Manual: Gao Yisheng's Bagua Twisting-Body Connected Palm. North Atlantic Books. ISBN978-15-839-4622-0.