Khai Sheang Lee, Hean Tat Keh, and Tuck Siong Chung. “SINGLE VESUS MULTIPLE SOURCE PURCHASING STRATEGY”. Asian Academy of Management Journal 5, no. 1 (June 29, 2000). Accessed July 3, 2024. https://ejournal.usm.my/aamj/article/view/aamj_vol5-no-1-2000_3.