Ilyas, M., S. M. Alfareed Zafar, M. Javed, and M. A. Mughal. “Association of Hypovitaminosis D With Hypertensive Disorder of Pregnancy”. Annals of Punjab Medical College (APMC), Vol. 14, no. 3, Sept. 2020, pp. 241-4, doi:10.29054/apmc/2020.932.