Plugin to provide in backend items from external sources for writing posts?

Hi,
I’m searching a plugin that would show up in the backend’s create-post page so that authors/contributors could easily while writing add links to external sources into their posts, for example by drag and drop. These links to external sources on other blogs should be available as (searchable) list and they should be acquired through their feeds.
This plugin would help to use and link to sources from a pre-defined pool of feeds and authors would not have to change to other browser windows, search the sources, copy the label and URL etc.
Can anyone give me a hint if this does exist?
thanks!