This literature review is the first section of a two part literature review in population dynamics focussing on a review of key global information sources. Three sources of centrally generated projections exist: The Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, the World Bank and the Wittgenstein Centre. As the World Bank relies heavily on the UN, its role will not be considered. The premier source of population projections is the UN Population Division. This data is easily accessible and updated every two years. Five global datasets are produced by the Division (i) World Population Prospects, (ii) World Urbanisation Prospects, (iii) World Population Policies, (iv) Estimates of family planning indicators and (v) Estimates of the number of international migrants.