Isfaizah, I., and C. Cahyaningrum. “***[RETRACTED]*** Effectiveness of Ferro Sulfate Supplementation on Hemoglobin and Ferritin Levels of Trimester I Pregnant Women”. Unnes Journal of Public Health, Vol. 8, no. 1, Jan. 2019, pp. 51-56, doi:10.15294/ujph.v8i1.22131.