ok just a minute a go i was seaching for somehting, many files came up claiming to have sources in the double and even triple digits. when i went to download these, many of them said "need more sources" but one of them was actually downloading, when i looked at the difference between these files i found that with the files i was able to download i was also able to browse host. I coulnd do this with any of the files that needed more sources. when i searched it again i found that this trick also works before you start the download. This way you can eliminate all the files that need more sources.
SO my advise is: if you can browse the host then there is high chance of finding valid sources.