personal Flat for couple with reasonableprice

We have plan to move Brussels for my wife's PhD study in ULB. we are now looking personal flat (studio or apartment) with reasonable price. They are some websites where I can see. However, do you have any suggestions (where should we live, and why, or do you have any apartment to give us to rent) pls? we are both student minded (pls don't be wrong, we both like to do study and students). We are non-EU. South Asian origin. from Bangladesh.