1. Select File > Add Entry Manually for Mendeley Desktop, or + Add > New manual entry for Mendeley Web.
2. Choose the relevant reference Type eg Journal Article. Fill in the fields following the Mendeley data entry conventions, and click 'Save' to finish.
Tip: You can use a DOI, PMID or ArXiv ID to look up the details of a reference. Paste the identifier into the appropriate field, and click on the magnifying glass. This will look up the item in the Mendeley Catalog and return the details provided by other Mendeley users. If the reference is completely new to Mendeley, the details will be retrieved directly from the appropriate identification service.