Marpaung, B., A. R. Ginting, and O. M. Sjah. “Serum Midkine Levels in Systemic Lupus Erythematosus”. Open Access Macedonian Journal of Medical Sciences, vol. 6, no. 8, Aug. 2018, pp. 1323-7, doi:10.3889/oamjms.2018.315.