Holmgren, D. (2002). Permaculture: Principles and pathways beyond sustainability. Holmgren design services.
Citazione stile Chigago Style (17a edizione)Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Victoria: Holmgren design services, 2002.
Citatione MLA (9a ed.)Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Holmgren design services, 2002.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.