_:n75608de65fe3427bbcbdb9fdbcd986b2xb1
<http://schema.org/image>
<https://static-content.springer.com/image/art%3A10.1186%2F1471-2288-13-129/MediaObjects/12874_2013_Article_1008_Fig1_HTML.jpg>
<https://bmcmedresmethodol.biomedcentral.com/articles/10.1186/1471-2288-13-129>