There are plenty of articles out there in teaching journals about L1 support for language learners and how helpful that can be.
I wrote an article review examining 4 articles on reading with hints of L1 support. I can send you that if you'd wish.
As for articles try
http://scholar.google.com/ and search. If you can't access the paper because it's subscription based try contacting the author directly. They'll usually send you a copy.