Butt, G., F. Zia, and I. Hussain. “Sudden Bilateral Blackish Discoloration of Toes in Middle-Aged Female”. Journal of Pakistan Association of Dermatologists, vol. 26, no. 1, Nov. 2016, pp. 87-89, https://www.jpad.com.pk/index.php/jpad/article/view/83.