Lutz, W. <https://pure.iiasa.ac.at/view/iiasa/190.html> ORCID: https://orcid.org/0000-0001-7975-8145 <https://orcid.org/0000-0001-7975-8145>  (1996).  The Future Population of the World: What Can We Assume Today?     London: Earthscan.  ISBN 1853833495