@article{Wellings2013,
author = {Wellings, K. and Jones, K.G. and Mercer, C.H. and Tanton, C. and Clifton, S. and Datta, J. and Johnson, A.M.},
title= {The prevalence of unplanned pregnancy and associated factors in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3},
year = {2013},
doi = {10.1016/S0140-6736(13)62071-1},
volume = {382},
number = {9907},
pages = {1807--1816},
}