PhD students seeks room in Bonn

I am looking for a furnished room in a shared flat, starting as soon as possible. The flat should be located within 15-20 minutes reach to the center of Bonn via public transports, have a washing machine and a functioning kitchen. I am flexible with all the other aspects.
I am 26 and I am doing my PhD in Mathematics in Bonn. I am a tidy person, I don't smoke, I enjoy sports (I go running and I climb regularly) and I am very sociable, but I respect other people's privacy. I've been living in shared flats for many years and I always had good relations with my flatmates. I am fluent in English and Italian and I speak a little (A2) German.