@phdthesis{UNY1736,
           title = {UPAYA MENINGKATKAN KEMANDIRIAN BELAJAR MATEMATIKA SISWA SMP NEGERI I MINGGIR MELALUI PENERAPAN PROBLEM- BASED LEARNING },
          school = {UNY},
          author = {Wuryastuti Esti},
            year = {2008},
             url = {http://eprints.uny.ac.id/1736/}
}