room not far from the Monsanto park

I’m a PhD student coming from Czech for an internship at Instuto Superior Technico in Lisbon. I’m looking for a private room in a fully furnished student flat situated nearby the Monsanto park. I prefer a calm neighborhood instead of city center. I wold like to stay in company of other students.  I'm willing to pay no more than 250 eur (all expenses included – gas, electricity, internet).