Filters add search terms to narrow your results.
PubMed Filters categorized and appear on the left hand side of a search result as follow:
Click on Additional Filters, to filter the search result, and apply one or combination of a few filters at the same time.
The image below displays the result of a search on Arrhythmia & Exercise in Mesh Database and filtered to publication date, and article type; randomized controlled trial.
Click on the icon as it's displayed and highlighted in the image to sort the the displayed search result by Best Match or Publication Date.
Export Citations into Citation Management
Use PubMed Cite Feature to export citations to free online softwares such as Zotero & Mendeley, or Endnote & Refworks (if you have individual subscription). You may format the citation to AMA, MLA, APA, and NLM bibliographic style; save or copy the text, then export to the designated citation manager.
PubMed generates a PermaLink (Permanent Link) for each citation in your search result. This will allow you to share the citation on different social media such as Twitter or FaceBook. See the image below: