Most of my private students tend to use ATPL Questions for Austro EASA exams, other QBs are available eg. ATPLGS, Bristol Ground School, I am sure there are others too. They all tend to more or less the same thing, it is important you can select questions by examining authority (UK CAA, Austro etc) and a very popular technique is to go through the last 200 questions seen. For Austro all questions are multi-choice whereas the UK CAA have some 'type in' or boxed answers you have to complete.
I assume you have done the FAA system, well you are in for a shock as to the sometimes dire standard of question both in terms of relevance but also grammar. However good your school is in terms of teaching material/instruction you are unlikely to pass the EASAs without the use of a QB.
Any questions please feel free to PM me.
Richard (Semi-retired ATPL theory instructor).