Holmgren, D. (2002). Permaculture: Principles and pathways beyond sustainability. Holmgren design services.
Chicago-viite (17. p.)Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Victoria: Holmgren design services, 2002.
MLA-viite (9. p.)Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Holmgren design services, 2002.
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