De Santis, A., Gaya-Piqué, L., Dominici, G., Meloni, A., Torta, J. M. and Tozzi, R. (2003) “ITalian Geomagnetic Reference Field (ITGRF): update for 2000 and secular variation model up to 2005 by autoregressive forecasting”, Annals of Geophysics, 46(3). doi: 10.4401/ag-3422.