@article{Keyfitz1972,
author = {Keyfitz, N.},
title= {On future population},
year = {1972},
doi = {10.1080/01621459.1972.10482386},
URL = {https://doi.org/10.1080/01621459.1972.10482386.},
volume = {67},
number = {1},
pages = {347--363},
}