Faizal Bin Omar, Mohd, Bambang Trigunarsyah, and Johnny Wong. “Two-Envelope System for Consultant Selection Using Weighted Sum Model”. International Journal of Engineering & Technology 7, no. 4.27 (November 30, 2018): 121–125. Accessed May 3, 2024. https://sciencepubco.com/index.php/ijet/article/view/22498.