VALACH, F., VÁCZYOVÁ, M., DOLINSKÝ, P. and VAJKAI, M. 2013. Substitution for lost one-hour means of the geomagnetic elements for the first half of the 20-th century at the Hurbanovo Geomagnetic Observatory by means of neural networks. Contributions to Geophysics and Geodesy. 43, 2 (Jun. 2013), 125-140. DOI:https://doi.org/10.2478/congeo-2013-0008.