_:nb5aa47742e0940fda9430526995212d8xb1
<http://schema.org/image>
<https://static-content.springer.com/image/art%3A10.1186%2F1471-2458-6-50/MediaObjects/12889_2005_Article_347_Fig1_HTML.jpg>
<https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-6-50/metrics>