?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Mollema&rft.au=Mollema%2C+M&rft.aufirst=M&rft.degree=Bachelor&rft.date=2013&rft.title=Earthquakes+above+the+Groningen+gasfield