If you're referring strictly to your university fees, then a side job should be enough, depending on your age. Information over how much you SHOULD be earning you can find here:
In case you're looking to cover all/ most of your expenses here in the Netherlands, a job is still the best place to start. Working 56 hours each month entitles you to social support, in the form of loans, grants or services offered by the Dutch government. More information here:
Hope this helps!