@phdthesis{UNY12769,
           month = {June},
          author = {Purwoko Wahyu Hutama},
           title = {Kajian Strategi Siswa dalam Menyelesaikan Sistem Persamaan Linear Dua Variabel},
          school = {UNY},
            year = {2014},
             url = {http://eprints.uny.ac.id/12769/}
}