Fowler, A. (2000). The virtuous spiral: A guide to sustainability for non-governmental organisations in international development. Earthscan.
Cita Chicago (17th ed.)Fowler, Alan. The Virtuous Spiral: A Guide to Sustainability for Non-governmental Organisations in International Development. London ; Sterling, VA: Earthscan, 2000.
Cita MLA (8th ed.)Fowler, Alan. The Virtuous Spiral: A Guide to Sustainability for Non-governmental Organisations in International Development. Earthscan, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.