This image shows the features of the Bibliography section of the timeline. The text talking about the features for the Bibliography section follows:

• Produce a list of scientific references supporting the facts presented in your timeline. Click More Options at the top of the page, then select Show Bibliography.
• Find all pages on ehd.org referencing a particular source by clicking Search EHD.
• Visit the National Library of Medicine's PubMed to view the abstract and full reference of a particular source by clicking Ref./Abstract.