Jančev, Mitko, Ivan Boev, Zdenka Stojanovska, & Blažo Boev. " CHARACTERIZATION OF PHOSPHOGYPSUM FROM DUMPS OF VELES PHOSPHATE FERTILIZER FACTORY (NORTH MACEDONIA) AND ENVIRONMENTAL IMPLICATIONS." Geologica Macedonica [Online], 33.2 (2019): 111-124. Web. 10 Aug. 2020