Galunska, B., B. Roussev, D. Gerova, and P. Kossev. “VITAMIN D: A POTENTIAL BIOMARKER FOR MORE AGGRESSIVE PROSTATE CANCER”. Biological Markers in Fundamental and Clinical Medicine (collection of Abstracts), Vol. 2, no. 2, Nov. 2018, pp. 23-24, doi:10.29256/v.02.02.2018.escbm16.