1. Chinese Academy of Preventive Medicine. 1992. National Standards for Labour Hygiene. Beijing: China Standards Publishers. p 143. (In Chinese).
2. 1994. Inorganic dusts. In: editors. Hunter's diseases of occupations, 8th ed. London: Edward Arnold. pp 410-57.
3. International Labour Office (ILO). 1990. ILO International Classification of Radiographs for Pneumoconioses. Geneva: International Labour Office.
4. Ministry of Health, People's Republic of China. 1998. Roentgeno-diagnosis of pneumoconioses GB5906-1997. Beijing: China Standards Publisher. (In Chinese).
5. 1990. Normal values of lung function in China. Beijing: Beijing Medical University and Peking Union Medical College. (In Chinese).