Small flat for young Russian scientist's couple

Hello,
We are a young and quiet married couple (24 and 25 years old) from Russia. We are students of Joint European Master in Nuclear Fusion Science and Engineering Physics (Erasmus Mundus programme). We are going to come to Jülich for 5-6 months to do the master thesis in Forschungszentrum. We are calm, we don't smoke, don't have children, don't have pets. We look for a nice and quiet flat with furniture and equipped kitchen. Important is that we need a flat only for 5-6 months, not very big but not less than 30m2, and we are ready to pay up to 500 euro per month including all payments, depending on the flat of course :) Unfortunately, we don't speak German, sorry...