The Physics of Breaking In Taekwondo, presentation from US Cup, October 13, 2018 (Rev. A, 15 OCT 2018, PDF 6.5MB)
The Physics of Breaking in Taekwondo photo gallery, June 2018 (photos used in above presentation, without annotation)
The Physics of Karate, Scientific American, 1979 (reference used in above presentation, PDF 6.1 MB)
The Physics of Karate, AJP, September 1983 (reference used in above presentation, PDF 3.4 MB)