Add your sources into the text field. If it matches, those sources will be added to searches automatically...sort of.
For now, this is quirky. Matching sources will be selected invisibly when the page loads. After searching, they will appear as usual. If they are explicitly deleted, they will not be used in the next search, but will be invisibly re-added for follow up searches.
This add-on will likely break without notice when DnD Beyond changes. It should be fairly quick and easy to fix again, but there will be delay.
https://github.com/th7/mysources
