@phdthesis{repository58866,
           title = {Peningkatan Konsentrasi Dan Hasil Belajar Materi Perkalian Menggunakan Model Problem Based Learning Siswa Kelas IV SDN Ngawen IV},
          school = {Sanata Dharma University},
          author = {ERIKA PATMA NUGRAHENI},
            year = {2026},
             url = {http://repository./58866/}
}