@article{Downs1996,
author = {Downs, A.M. and De Vincenzi, I.},
title= {Probability of heterosexual transmission of HIV: Relationship to the number of unprotected sexual contacts},
year = {1996},
journal = {Journal of Acquired Immune Deficiency Syndrome and Human Retrovirology},
volume = {11},
pages = {388--395},
}