:) The BBC are usually quite good with directly linking their sources, when it's reports or studies (or anything in PDF form). The Guardian are similarly good in that regard, too.
On law/crime articles, they don't link to legal judgments. That's partly the fault of the British legal system for not publishing a lot of that material. But there are plenty of times when it is available and it doesn't get linked to.
Hypertext is a thing. One day people will work out all the amazing possibilities.