Chockalingam, Nachiappan and Robert L Ashford. “Selected foot length ratios in a non-pathological sample”. Revista Internacional de Ciencias Podológicas, vol. 1, vol. 1, no. 2, 2007, pp. 25-30, https://revistas.ucm.es/index.php/RICP/article/view/RICP0707220025A.