@Article{angeo-33-109-2015,
AUTHOR = {Lundstedt, H. and Persson, T. and Andersson, V.},
TITLE = {The extreme solar storm of May 1921: observations and a complex topological model},
JOURNAL = {Annales Geophysicae},
VOLUME = {33},
YEAR = {2015},
NUMBER = {1},
PAGES = {109--116},
URL = {https://angeo.copernicus.org/articles/33/109/2015/},
DOI = {10.5194/angeo-33-109-2015}
}