1. Vergleichung der Sonnenfleckenkurven für die Jahre 1853–1939;Brunner-Haggar;Astron. Mitt. Zürich,1941
2. Sunspot and Geomagnetic-Storm Data 1874–1954;Jones,1955
3. Observation of Sunspots 1947–1984;Koyama,1985
4. Solar wind velocity effects on the auroral zone magnetic disturbances;Maezawa,1986
5. The aa indices: a hundred year series of geomagnetic data 1868–1967;Mayaud,1973