@article{ref1,
title="Physical activity and sedentary behaviors of urban Chinese children: grade level prevalence and academic burden associations",
journal="BioMed research international",
year="2017",
author="Zhu, Xihe and Haegele, Justin A. and Tang, Yan and Wu, Xueping",
volume="2017",
number="",
pages="7540147-7540147",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="2314-6133",
doi="10.1155/2017/7540147",
url="http://dx.doi.org/10.1155/2017/7540147"
}