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Tseng MSF, Zheng H, Ng IWS, Leong YH, Leong CN, Yong WP, Cheong WK, Tey JCS.Tseng MSF, et al.Singapore Med J. 2018 Jun;59(6):305-310. doi: 10.11622/smedj.2017105. Epub 2017 Nov 13.Singapore Med J. 2018.PMID: 29167909Free PMC article.