@article{Barbieri2005,
author = {Barbieri, M. and Hertrich, V. and Grieve, M.},
title= {Age difference between spouses and contraceptive practice in sub-Saharan Africa},
year = {2005},
doi = {10.2307/4148187},
volume = {60},
number = {5–6},
pages = {617--654},
}