M. D. Oancea, N. Costin, D. M. Pop, R. Ciortea, and D. Mihu, “Evaluation Of Serum β-Hcg And Papp-A Levels In Pregnant Women At Risk Of Developing Preeclampsia”, Med Pharm Rep, vol. 86, no. 4, pp. 347–351, Feb. 2014.