Willis, D. M., Vaquero, Jose M. and Stephenson, F. Richard. (2009) Early observation of the aurora australis: AD 1640. Astronomy & Geophysics, Vol.50 (No.5). pp. 20-24. ISSN 1366-8781

Willis, D. M., Henwood, R. and Stephenson, F. R.. (2009) The presence of large sunspots near the central solar meridian at the times of major geomagnetic storms. Annales Geophysicae, Vol.27 (No.1). pp. 185-197. ISSN 0992-7689