Suwankhan, S, B Chaiyaprasithi, and S Soontrapa. 2009. “Efficacy of intravesical capsaicin in chronic pelvic pain syndrome and painful bladder syndrome”. Insight Urology 30 (1):24-32. https://he02.tci-thaijo.org/index.php/TJU/article/view/252489.