Buyukberber, S., N. Buyukberber, M. Turgay, and G. Tokgoz. “Serum Immunoglobulin Levels in Systemic Lupus Erythematosus: Is IgA Level an Activity Criterion”. Annals of Medical Research, vol. 2, no. 4, May 2021, pp. 0336-42, http://annalsmedres.org/index.php/aomr/article/view/2466.