@article{savolainen_kovalev_2008, 
  title={Serendipitous VLBI detection of rapid, large-amplitude,   intraday
 variability in QSO 1156+295}, 
  volume={489}, 
  DOI={10.1051/0004-6361:200810423}, 
  publisher={EDP Sciences}, 
  author={Savolainen and Kovalev}, 
  year={2008}, 
  month={Sep}
  }