While using the Zotero Connector extension is the easiest way to add items individually, sometimes you may prefer to import groups of items into your Zotero library. The video below shows how to export sources from Library Search. Most databases will have an export option like this. For Zotero, choose the RIS or BibTeX file format for your download.
Note that Zotero may struggle with large file sizes. If you have trouble with the import, try doing it in batches.