1. Kenneth Pye Associates Ltd, Crowthorne Enterprise Centre, Crowthorne Business Estate
Crowthorne RG45 6AW, UK
kpye@kpal.co.uk
2. Department of Geology, Royal Holloway, University of London
Egham Hill, Egham TW20 0EX, UK
3. Croft Scientific & Technical, Blaen-y-Waun
Llanafan, Ceredigion SY23 4BD, UK