Dyfyniad APA

Holmgren, D. (2002). Permaculture: Principles and pathways beyond sustainability. Holmgren design services.

Dyfyniad Arddull Chicago

Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Victoria: Holmgren design services, 2002.

Dyfyniad MLA

Holmgren, David. Permaculture: Principles and Pathways Beyond Sustainability. Holmgren design services, 2002.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.