Birch, Martin John, Hargreaves, J. K., Senior, A. and Bromage, B. J. I. (2007) Correlation of ring current indices with invariant latitude cutoff for three SEP events from 2001. In: National Astronomy Meeting (NAM) 2007, 16-20 April 2007, University of Central Lancashire, Preston, United Kingdom.
Birch, Martin John, Hargreaves, J. K., Bromage, B. J. I. and Senior, A. (2004) Three proton events in 2001. In: Conference on Sun-Earth Connections, 9 February 2004, Kona, Hawaii.
Birch, Martin John, Hargreaves, J. K., Senior, A. and Bromage, B. J. I. (2003) Variations of Cutoff Latitude for Selected Solar Energetic Proton Events. In: EGS-AGU-EUG Joint Assembly,, 6-11 April 2003, Nice, France.