?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=ter+Beek%2C+Maurice+H.&rft.aufirst=Maurice+H.&rft.aulast=ter+Beek&rft.title=Combining+Declarative+and+Procedural+Views+in+the+Specification+and+Analysis+of+Product+Families&rft.date=May+2013&rft.genre=proceeding