Ahmed, Ishtiaq, et al. “Comparison of Metformin Plus Nicotinamide Solution With Kligman Formula in the Management of Melasma- a Clinical Trial in a Tertiary Care Hospital”. Pakistan Armed Forces Medical Journal, vol. 76, no. SUPPL-2, Mar. 2026, pp. S340-S343, https://doi.org/10.51253/pafmj.v76iSUPPL-2.10432.