1. The Water Conservancy Ministry of China, Hydrological Yearbook, 1958–1990 (in Chinese).
2. The Statistic Bureau of China, The Statistic Yearbook of Chinese Industrial Economics, The Statistic Publishing House of China, Beijing (1991) (in Chinese).
3. The Statistic Bureau of China, Rural Statistic Yearbook of China, 1993, The Statistic Publishing House of China, Beijing (1993) (in Chinese).
4. The Statistic Bureau of China, The Statistic Yearbook of China, The Statistic Publishing House of China, Beijing (1990) (in Chinese).