INRA: - ስለ permaculture ኢኮኖሚያዊ ጥናት - ግብርና እና ምግብ ፣ እራስዎ ያድርጉት (DIY): እራስዎ ያድርጉት!
INRA: economic study of permaculture - Agriculture and Food, Do It Yourself (DIY): make it yourself !, Study Report to download, Downloads