The “Four Keys to Sustainable Settlements”, or just the “Four Keys”, are anthologies published by Gaia Education to supplement the EDE course material. They cover the four sectors of the sustainability circle, namely, the Worldview, Social, Ecological and Economic dimensions. Each book covers the five modules of its section. Written by pioneers from the ecovillage movement and teachers of the EDE, they include both articles and extensive references.
They are all available on the Gaia Education website for gratis downloading. Permanent Publis, UK offer “print on demand” hard copies to interested parties for a normal printing fee.