Sahlu , A. ., and A. . Dinku. “Construction Site Wastes (non-Physical) Categorization in Addis Ababa Based on Lean Concept”. Zede Journal of Ethiopian Engineers and Architects, vol. 39, Feb. 2023, pp. 31-43, http://ejol.aau.edu.et/index.php/ZEDE/article/view/6551.