?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Sofiati&rft.aufirst=Tatik&rft.au=Sofiati%2C+Tatik&rft.title=USING+TIERED+ACTIVITIES+TO+IMPROVE+THE+WRITING+SKILLS+OF+THE+SEVENTH+GRADE+STUDENTS+OF+MTs+N+YOGYAKARTA+1+IN+THE+ACADEMIC+YEAR+OF+2013%2F2014&rft.date=27+October+2014&rft.inst=Universitas+Negeri+Yogyakarta&rft.degree=S1