Comparison of the Polynomial Regression Zonal Estimation Comparison of the Inverse Distance Weighting and Ordinary Kriging Linear Interpolator: Case Study of Porosity Estimation in Neogene Sandstone Reservoirs in the Sava Depression, Croatia. Rud.-geol.-naft. zb. 2025;40(4):185-196. doi:10.17794/rgn.2025.4.14