1. Ningxia Center for Disease Control and Prevention Yinchuan Ningxia China
2. College of Public Health Ningxia Medical University Yinchuan Ningxia China
3. Department of Cell and Molecular Biology QIMR Berghofer Medical Research Institute Herston Queensland Australia
4. Eastern Health Library Service Maroondah Hospital Box Hill Victoria Australia
5. Department of Epidemiology and Health Statistics College of Public Health Zhengzhou University Zhengzhou Henan China