_:nb141e0c604224b9b941533e83931eec3xb1
<http://schema.org/headline>
"The denominator problem: Estimating MSM-specific incidence of sexually transmitted infections and prevalence of HIV using population sizes of MSM derived from Internet surveys"
<https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-9-181>