In all
seriousness, I think the policy should be that any special knowledge
needed to understand the article should be included somewhere in Wikipedia.
So foreign language sources are out, then? I think that's a good
guideline in a lot of situations, but not all... some types of
specialist knowledge aren't the kinds of things you find in an
encyclopedia.
We have Wikibooks about learning different language, and Wiktionaries
about the meanings of words. If language is your problem maybe you
could start by looking there.
Ec