Matzka, J. 2.3 Earth's Magnetic Field, 2.0 Geophysics, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Matzka, J. (2015): Determining, and accounting for, spatial gradients of the geomagnetic field in observatories. - Scientic programme, 26th IUGG General Assembly (Prague 2015).