Polygon “Simeiz-Katsively” - changes in the average pole of the Earth and the geomagnetic field over the last centuryLarisa Volvach, Galina Kurbasova, Andrej Dmytrotsa and Dmitry NeyachenkoITM Web Conf., 30 (2019) 15004DOI: https://doi.org/10.1051/itmconf/20193015004