Raja Taihairan, Raja Bukhary, and Zulhabri Ismail. “BIM: Integrating Cost Estimates at Initial/Design Stage”. International Journal of Sustainable Construction Engineering and Technology 6, no. 1 (October 25, 2015): 62-74. Accessed December 13, 2019. https://publisher.uthm.edu.my/ojs/index.php/IJSCET/article/view/1122.