Knowledge domain and emerging trends in chronic prostatitis/chronic pelvic pain syndrome from 1970 to 2020: a scientometric analysis based on VOSviewer and CiteSpace - Liu, Sheng-Jing; Gao, Qing-He; Deng, Ying-Jun; Zen, Yin; Zhao, Ming; Guo, Jun (Annals of Palliative Medicine, 2022)