Wright, A. D., Cull, C. A., Holman, R. R., & Turner, R. C. (1998). UKPDS 28: A randomized trial of efficacy of early addition of metformin in sulfonylurea-treated type 2 diabetes. DIABETES CARE, 21(1), 87–92.

Wright, A. D., et al. “UKPDS 28: A Randomized Trial of Efficacy of Early Addition of Metformin in Sulfonylurea-Treated Type 2 Diabetes.” DIABETES CARE, vol. 21, no. 1, 1998, pp. 87–92.

Wright, AD, CA Cull, RR Holman, and RC Turner. 1998. “UKPDS 28: A Randomized Trial of Efficacy of Early Addition of Metformin in Sulfonylurea-Treated Type 2 Diabetes.” DIABETES CARE 21 (1): 87–92.