?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aufirst=Widayanti&rft.au=Erni%2C+Widayanti&rft.aulast=Erni&rft.title=SMARANDACHE+SEMIRING+DAN+SIFAT-SIFATNYA&rft.degree=S1&rft.date=2006&rft.inst=UNY