Ismailova C, Golkocheva-Markova E, Tenev T, Krumova S. THE USE OF DRIED BLOOD SPOTS FOR MEASURING THE IMMUNITY AGAINST HBV: THE SIGNIFICANCE OF ANTIBODY DILUTION. Probl Infect Parasit Dis. 2019;47(1):16-20. doi:10.58395/pipd.v47i1.12