How can I import citations for PDFs and webpages
The Scrible Toolbar will do its best to try to pick up citation information automatically for databases and websites, but there are cases where it can't do that.
In particular, if you've downloaded a PDF from a database, Scrible won't be able to retrieve citation information automatically. There may also be cases where citation information for web based pages from databases won't be picked up.
But don't worry, if you go back to the database and find the article again, most databases offer a citation export feature which allows you to download the citation in RIS format (sometimes also labeled as EndNote or Citavi). Download this RIS file, and then go back to the citation editor for that source (in the Citation sidebar in the Toolbar, or editing the source in one of the Bibliography views or editing the source in the Sources tab of the library.)
If you are doing all of this in tabs of the same browser window, the downloads bar should still be showing with that RIS file - just drag and drop it right into the citation editor and it will update the citation editor with the RIS data. If you don't have the downloads bar available, just scroll to the bottom of the citation editor and click the "Import citation or drag RIS file here" link to open a file picker - just chose the RIS file you downloaded and it will load it into the citation editor.
Here's some information on how to download the RIS for a few of the major databases.
Click on the "Cite" button in the header bar.
Then in the dialog that opens click on the "Download RIS"
From the Tools sidebar, choose the "Cite" option
Then in the main screen that opens, choose "Export to Bibliography Management Software" link at the bottom
and then choose the "Direct Export in RIS Format" option and click "Save".