An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Oh JT, Koh H, Chang EY, Chang HK, Han SJ.Oh JT, et al. Among authors: chang ey, chang hk.J Korean Med Sci. 2012 Jun;27(6):701-3. doi: 10.3346/jkms.2012.27.6.701. Epub 2012 May 26.J Korean Med Sci. 2012.PMID: 22690105Free PMC article.
Chang HK, Koh H, Hong YJ, Chang EY, Han SJ, Oh JT.Chang HK, et al. Among authors: chang ey.Yonsei Med J. 2014 Jan;55(1):157-61. doi: 10.3349/ymj.2014.55.1.157.Yonsei Med J. 2014.PMID: 24339301Free PMC article.
Park SM, Shukri N, Chang EY, Ho IG, Han SJ.Park SM, et al. Among authors: chang ey.J Laparoendosc Adv Surg Tech A. 2016 Jun;26(6):488-92. doi: 10.1089/lap.2015.0521. Epub 2016 May 2.J Laparoendosc Adv Surg Tech A. 2016.PMID: 27135355Clinical Trial.
Chang HK, Chang EY, Ryu S, Han SJ.Chang HK, et al. Among authors: chang ey.Yonsei Med J. 2016 Jul;57(4):893-9. doi: 10.3349/ymj.2016.57.4.893.Yonsei Med J. 2016.PMID: 27189282Free PMC article.Clinical Trial.