Purwaningsih, R., Simanjuntak, C.F. and 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 (Jun. 2020), 47-54. DOI:https://doi.org/10.9744/jti.22.1.47-52.