## 6.4 References

References can be displayed as margin notes for HTML output. To enable this feature, you must set link-citations: yes in the YAML metadata, and the version of pandoc-citeproc should be at least 0.7.2. To check the version of pandoc-citeproc in your system, you may run this in R:

system2('pandoc-citeproc', '--version')

If your version of pandoc-citeproc is too low, or you did not set link-citations: yes in YAML, references in the HTML output will be placed at the end of the output document.

You can also explicitly disable this feature via the margin_references option, e.g.,

---
output:
tufte::tufte_html:
margin_references: false
---