Hasni, ., and Hiras Manulang. “PERANAN SEKTOR BAJA DALAM PEREKONOMIAN INDONESIA”. Buletin Ilmiah Litbang Perdagangan, vol. 5, no. 1, July 2011, pp. 22-46, https://jurnal.kemendag.go.id/index.php/bilp/article/view/119.