Skeivalas, J., Paršeliūnas, E., Putrimas, R. and Šlikas, D. 2012. Analysis of code levelling rods calibration accuracy applying covariance functions. Geodesy and Cartography. 35, 2 (Aug. 2012), 39-43. DOI:https://doi.org/10.3846/1392-1541.2009.35.39-43.