Mamanee, Pornthep, Nathapon Chantaraseno, and Somsak Geraplangsub. “Os Trigonum Syndrome or Posterior Ankle Impingement (PAI)”. The Bangkok Medical Journal 7, no. 1 (February 20, 2014): 94. Accessed August 11, 2020. https://he02.tci-thaijo.org/index.php/bkkmedj/article/view/219633.