Daniel Goodkind; Loraine West; Peter Johnson (28 March 2011). A Reassessment of Mortality in North Korea, 1993–2008. Annual meeting of the Population Association of America March 31-April 2, 2011. Washington, D.C. U.S. Census Bureau, Population Division. p. 3. Archived from the original on 17 September 2019. Retrieved 8 November 2014.
Daniel Goodkind; Loraine West; Peter Johnson (28 March 2011). A Reassessment of Mortality in North Korea, 1993–2008. Annual meeting of the Population Association of America March 31-April 2, 2011. Washington, D.C. U.S. Census Bureau, Population Division. p. 3. Archived from the original on 17 September 2019. Retrieved 8 November 2014.