1. GLE Database., https://gle.oulu.fi.
2. Solar Monitor., https://www.solarmonitor.org/index.php?date=19980824®ion08307.
3. https://cdaw.gsfc.nasa.gov/CME_list.
4. ftp://ftp.swpc.noaa.gov/pub/warehouse.
5. Gopalswamy, N., in Planetary Radio Emissions VII, Vienna: Springer, 2011, p. 325.