E. O. Darkwa, R. Djagbletey, R. Essuman, D. Sottie, G. B. Dankwah, and G. Aryee, “Nitric Oxide and Pre-Eclampsia: A Comparative Study in Ghana”, Open Access Maced J Med Sci, vol. 6, no. 6, pp. 1023–1027, Jun. 2018.