Whitehead, M., Petticrew, M., Graham, H., Macintyre, S., Bambra, C., & Egan, M. (2004). Evidence for public health policy on inequalities II: Assembling the evidence jigsaw. Journal of Epidemiology and Community Health, 58(10), 817-821. https://doi.org/10.1136/jech.2003.015297