Stratified sampling method was applied to investigate immunization status of ecdemic children and its affecting factors in Baoshan District.
方法采用分层抽样方法对本区外来流动儿童免疫接种现状及其影响因素进行流行病学调查。
Stratified sampling method was applied to investigate immunization status of ecdemic children and its affecting factors in Baoshan District.
方法采用分层抽样方法对本区外来流动儿童免疫接种现状及其影响因素进行流行病学调查。
应用推荐