1. Hamilton, et al. (2011). The PhenX toolkit: Get the most from your measures. American Journal of Epidemiology,174(3), 253–260.
2. He, W., Hu, X., Hou, Y., et al. (2018). The development of economic security system for the elderly people in China. In P. Du, J. Lu, & W. He (Eds.), Annual Report on Development of Actively Coping with Population Ageing in the New Era (2018). Beijing: Hualing Press. (in Chinese).
3. Hu, R. (Ed.). (1991). Elderly population survey in nine cities in China, 1998. Tianjin: Tianjin Education Press. (in Chinese).
4. Peng, X., & Hu, Z. (2015). The contemporary transition of the Chinese family and the reconstruction of family policy. Social Sciences in China,12, 113–132.
5. Tian, X. (1988). A profile of elderly population in China: Report from age 60 and above elderly population sampling survey in 1987. Chinese Journal of Population Science,8(5), 1–9. (in Chinese).