Zheng, Xiaozhi, Ping Ji, Hongwei Mao, and Jing Wu. “Evaluation of Penile Erection Rigidity in Healthy Men Using Virtual Touch Tissue Quantification”. Radiology and Oncology 46, no. 2 (June 1, 2012). Accessed June 12, 2026. https://www.radioloncol.com/index.php/ro/article/view/948.