@article{Ahmed00,
author = {Ahmed, S. and Li, Q. and Liu, L. and Tsui, A.O.},
title= {Maternal deaths averted by contraceptive use: an analysis of 172 countries},
doi = {10.1016/S0140-6736(12)60478-4},
journal = {The Lancet},
volume = {380},
number = {9837},
pages = {111--125},
}