Widiana, I. W., and N. P. W. Sucidamayanti. “PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE NUMBERED HEADS TOGETHER UNTUK MENINGKATKAN HASIL BELAJAR IPS”. International Journal of Elementary Education, vol. 1, no. 1, July 2017, pp. 52-61, doi:10.23887/ijee.v1i1.11439.