Purwaningsih, R., Simanjuntak, C. F., & Rosyada, Z. F. (2020). Eco-Efficiency of Pencil Preduction Using Life Cycle Assessment to Increase the Manufacture Sustainability. Jurnal Teknik Industri: Jurnal Keilmuan Dan Aplikasi Teknik Industri, 22(1), 47-54. https://doi.org/10.9744/jti.22.1.47-52