?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Bacigalupo&rft.au=Bacigalupo%2C+Andrea&rft.aufirst=Andrea&rft.date=August+2013&rft.title=Acoustic+velocity+in+layered+rock+masses+with+periodic+fractures&rft.genre=proceeding