S. Lestari, D. K. Sari, I. Fujiati, S. J. Martina, and N. H. Nasution, “Haemoglobin Levels of Adolescent Girls Aged 11-19 Years in North Sumatera are Correlated with Socio-Economic Status and Menstrual Cycle Duration”, Pak. J. Nutr., vol. 19, no. 3, pp. 122–126, Feb. 2020, doi: 10.3923/pjn.2020.122.126.