Unfortunately, I could not meet Bojan and Katarina because they were in vacation. But Katarina's mother welcomed us very kindly and warmly even if we could not communicate with each other (we could not speak German and she could not English). And also, even though they were in vacation, they answered to my questions very quickly. The apartment was very clean and located in a very calm neighborhood. So I recommend it if you are looking for an accommodation in Vienna !