J. C. Nwanya, H. I. Mbachu, and K. C. N. Dozie. “Design Optimality Criteria of Reduced Models for Variations of Central Composite Design”. Archives of Current Research International 19, no. 4 (February 11, 2020): 1–7. Accessed October 16, 2025. https://www.journalacri.com/index.php/ACRI/article/view/324.