@article{Halperin2004,
author = {Halperin, D.T. and Epstein, H.},
title= {Concurrent sexual partnerships help to explain Africa's high HIV prevalence: Implications for prevention},
year = {2004},
doi = {10.1016/S0140-6736(04)16606-3},
journal = {The Lancet},
volume = {364},
number = {9428},
pages = {4--6},
}