Lavraud, B., Dunlop, M. W., Phan, T. D., Rème, H., Bosqued, J.-M., Dandouras, I., et al. (2002). Cluster observations of the exterior cusp and its surrounding boundaries under northward IMF. Geophysical Research Letters, 29(20): 1995. doi:10.1029/2002GL015464.