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. 2012 May 16;14(3):e74. doi: 10.2196/jmir.1943

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©Liupu Wang, Juexin Wang, Michael Wang, Yong Li, Yanchun Liang, Dong Xu. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 16.05.2012.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.

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