@book{United Nations1968,
author = {United Nations},
title= {The concept of a stable population: Application to the study of populations of countries with incomplete demographic statistics},
year = {1968},
URL = {http://www.un.org/en/development/desa/population/publications/manual/model/stable-population.shtml},
address = {New York},
publisher = {United Nations, Department of Economic and Social Affairs, Population Division},
}