VALACH F, VÁCZYOVÁ M, VÝBERČI D, KOČI E. Regular observations of the geomagnetic field at the Ógyalla observatory (present-day Hurbanovo) near the turn of the 20th century, including magnetic storms accompanied by auroras in March 1894, September 1898, and October 1903. Contrib. Geophys. Geod. 2025;54(1):23-48. doi:10.31577/congeo.2024.54.1.2