Rol cludiant rheilffyrdd : polisi rhanbarthol, adfywio'r cymoedd : menter: astudiaeth enghreifftiol ynghyd â phrosiectau amlddisgyblaeth by D. I. Trotman-Dickenson. ISBN 0948634480. Published by Politechnig Cymru in 1990. Publication and catalogue information, links to buy online and reader comments.