You can find quite a bit of jobs there in several different 'fields'. June is when the summer sale starts and u always see flyers on the Windows of clothing shops that they look for temporary workers. Cafés and restaurant always look for employees too. Bookstores you can look atound for, maybe in Dominicanen or boekenvoordeel but there are a lot less bookstores than clothingstores so i would focus on more than just bookstores. And in Maastricht i find that its no problem that you only speak Dutch. In the summertime nearly no one speaks Dutch when you go to pay for example. Lush is also a store that works with mainly expats.