Wu, C. C., Dryer, M., Smith, Z., Wu, S. T., & Lyu, L. H. (1996). Prediction of Solar-Flare-Caused Geomagnetic Storms. Terrestrial, Atmospheric and Oceanic Sciences, 7(2), 179-188. https://www.airitilibrary.com/Article/Detail?DocID=10170839-199606-7-2-179-188-a