Cao, X., Pu, Z. Y., Du, A. M., Mishin, V. M., Wang, X. G., Xiao, C. J., et al. (2012). On the retreat of near-Earth neutral line during substorm expansion phase: a THEMIS case study during the 9 January 2008 substorm. Annales Geophysicae, 30(1), 143-151. doi:10.5194/angeo-30-143-2012.