@article{Boily2009,
author = {Boily, M-C. and Baggaley, R.F. and Wang, L. and Masse, B. and White, R.G. and Hayes, R. and Alary, M.},
title= {Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies},
year = {2009},
doi = {10.1016/S1473-3099(09)70021-0},
journal = {The Lancet},
volume = {9},
pages = {118--129},
}