@phdthesis{UNY12706,
           title = {Pengaruh Model Pembelajaran Kooperatif Tipe Group Investigation terhadap Kemampuan Pemecahan Masalah Matematika dan Kreativitas Siswa SMP Kelas VIII},
            year = {2014},
          school = {UNY},
          author = {Umi Baroroh},
           month = {June},
             url = {http://eprints.uny.ac.id/12706/}
}