You've probably seen the Find It button in some article databases that allows you to locate the full text of an article online. Zotero allows you to use the same feature.
To set up Zotero to access the articles and books, click the gear button on the Zotero toolbar and choose Preferences. At the bottom of the preferences window, paste this url into the "Resolver" box:
Then click OK. Once you've set this up, you can click the Locate button on any citation you're viewing to search for the item online.
The link below launches a video that shows how to integrate Titan apps and Google Docs with Zotero.
First, enable PDF indexing on the Search tab of Zotero's preferences. Zotero will download and install a small plugin.
Next, just drag your PDF files into the Zotero pane.
Right-click the PDFs and choose "Retrieve Metadata for PDFs." Zotero will retrieve their citation data from Google Scholar and turn them into citeable items with PDF attachments.
If Zotero can't find a match on Google Scholar, don't worry -- you can still save the citation from another catalog or article database, then drag the PDF onto the citation to make it an attachment.