Historical World Population Comparison

Among others these are the original source:

McEvedy, Colin and Richard Jones, 1978, "Atlas of World Population History," Facts on File, New York, pp. 342-351.

Biraben, Jean-Noel, 1980, An Essay Concerning Mankind's Evolution, Population, Selected Papers, December, table 2.

Durand, John D., 1974, "Historical Estimates of World Population: An Evaluation," University of Pennsylvania, Population Center, Analytical and Technical Reports, Number 10, table 2.

Haub, Carl, 1995, "How Many People Have Ever Lived on Earth?" Population Today, February, p. 5.

Thomlinson, Ralph, 1975, "Demographic Problems, Controversy Over Population Control," Second Edition, Table 1.

United Nations, 1999, The World at Six Billion, Table 1, "World Population From" Year 0 to Stabilization, p. 5,
U.S. Census Bureau (USCB), 2012, Total Midyear Population for the World: 1950-2050.

Michael Kremer (1993) "Population Growth and Technological Change: One Million B.C. to 1990", Quarterly Journal of Economics., August 1993, pp.681-716.

Klein Goldewijk K, Beusen A, Janssen P (2010) "Long term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1". The Holocene 20:565-573.