Kimber-Trojnar, Żaneta, et al. “SFRP5-Leptin Ratio As a Promising Index in Post-Partum Women With Gestational Diabetes Mellitus”. Journal of Education, Health and Sport, vol. 9, no. 3, Mar. 2019, pp. 40-47, https://apcz.umk.pl/JEHS/article/view/6643.