Publication: Extremely intense (SML ¾­2500 nT) substorms: isolated events that are externally triggered?

Tsurutani, B. T., R. Hajra, E. Echer and J.W. Gjerloev (2015), Extremely intense (SML ¾­2500 nT) substorms: isolated events that are externally triggered?, Ann. Geophys., 33, 519-524, doi.org/10.5194/angeo-33-519-2015  (pdf)