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.
Cheung KL, Wijnen B, de Vries H.Cheung KL, et al.J Med Internet Res. 2017 Jun 23;19(6):e230. doi: 10.2196/jmir.7209.J Med Internet Res. 2017.PMID: 28645889Free PMC article.Review.
Cheung KL, Schwabe I, Walthouwer MJL, Oenema A, Lechner L, de Vries H.Cheung KL, et al.Int J Environ Res Public Health. 2017 Oct 23;14(10):1275. doi: 10.3390/ijerph14101275.Int J Environ Res Public Health. 2017.PMID: 29065545Free PMC article.Clinical Trial.
van Het Schip C, Cheung KL, Vluggen S, Hoving C, Schaper NC, de Vries H.van Het Schip C, et al. Among authors: cheung kl.J Med Internet Res. 2020 Apr 23;22(4):e15397. doi: 10.2196/15397.J Med Internet Res. 2020.PMID: 32324138Free PMC article.
Mutaz M, de Vries N, Cheung KL, de Vries H.Mutaz M, et al. Among authors: cheung kl.Tob Prev Cessat. 2020 May 15;6:29. doi: 10.18332/tpc/120000. eCollection 2020.Tob Prev Cessat. 2020.PMID: 32760864Free PMC article.