TCHERKEZOVA , milia ., STOYANOVA, elimira . and KOTSEV, T. . (2019) “A CONCEPT OF AN INTEGRATED GEODATABASE FOR SURFACE WATER, SOIL AND GROUNDWATER POLLUTION WITH ARSENIC IN THE UPPER PART OF OGOSTA VALLEY, NORTHWESTERN BULGARIA”, European Journal of Geography, 10(3). Available at: https://eurogeojournal.eu/index.php/egj/article/view/201 (Accessed: 17 October 2025).