Investigation of natural radioactivity in drinking water sources in South-Central Bulgaria. - Tonev, Dimitar; Geleva, Elena; Slavchev, Bozhidar; Dobrev, Lyuben; Protohristov, Hristo; Veleva, Blagorodka; Goutev, Nikolay; Demerdjiev, Anguel; Dimitrova, Desislava; Nikolova, Nina (Journal of Radioanalytical & Nuclear Chemistry, 2023)