by P. Mäntyniemi, E. S. Husebye, T. R. M. Kebeasy, A. A. Nikonov, V. Nikulin, A. Pacesa
Published in Annals of geophysics (01.06.2004)

by Gregersen, S., Wiejacz, P., Dębski, W., Domanski, B., Assinovskaya, B., Guterch, B., Mäntyniemi, P., Nikulin, V.G., Pacesa, A., Puura, V., Aronov, A.G., Aronova, T.I., Grünthal, G., Husebye, E.S., Sliaupa, S.
Published in Physics of the earth and planetary interiors (14.09.2007)