Krumova, S.; Golkocheva-Markova, E.; Angelova, S.; Voleva, S.; Pavlova, A.; Georgieva, I.; Genova-Kalou, P. Dried Blood Spots As a Clinical Samples for Laboratory Diagnosis and Surveillance of Vaccine-Preventable Diseases in Bulgaria. ASRJETS-Journal 2019, 51 (1), 183-191.