JARMOŁOWSKI, Wojciech, and Mieczysław BAKUŁA. “Two Covariance Models in Least Squares Collocation (LSC) Tested in Interpolation of Local Topography”. Contributions to Geophysics and Geodesy, vol. 43, no. 1, Mar. 2013, pp. 1-19, doi:10.2478/congeo-2013-0001.