Should I add a DOI as well as a URL in my reference?

Some reference styles require the DOI to be included, so it is best to understand the style requirements.

Including DOI in your reference list provides a direct and persistent link to the source, unlike URLs, which may expire.

If you are unable to find a DOI for a source, the URL will be sufficient.

Note - make sure you choose the right referencing template for DOI or URL links.