Application of multiple nonlinear regression models for short-term forecasts of karst aquifer water quality parameters: the example of Banja spring near Valjevo, Republic of Serbia. - Lončar, Jovana; Tanasković, Aleksandar; Vakanjac, Vesna Ristić; Golubović, Radisav; Marinović, Veljko; Petrović, Branislav (Review of the Bulgarian Geological Society, 2025)