Fowler, A. (2000). The virtuous spiral: A guide to sustainability for non-governmental organisations in international development. Earthscan.
芝加哥风格引文Fowler, Alan. The Virtuous Spiral: A Guide to Sustainability for Non-governmental Organisations in International Development. London ; Sterling, VA: Earthscan, 2000.
MLA引文Fowler, Alan. The Virtuous Spiral: A Guide to Sustainability for Non-governmental Organisations in International Development. Earthscan, 2000.
警告：这些引文格式不一定是100％准确.