Jin, Hao, et al. “Social Security Expenditure, Demographic Structural Changes, and Urban?Rural Income Gap in China: Evidence from the Provincial Data”. Revista de Cercetare Si Interventie Sociala, vol. 62, Sept. 2018, pp. 254-77, https://www.rcis.ro/journal/article/view/2463-social-security-expenditure-demographic-structural-changes.