Analysis of serum vitamin D level in children aged 2-6 years in urban area of Xi′an in summer
YOU Jia, TIAN Hui-zhen, CAO Chun-hong, CHEN Yan, HE Yu-ying, ZHENG Jing-jng
journal1 . 2018, (12): 1361 -1363 .  DOI: 10.11852/zgetbjzz2018-0548