1. ACGIH 1980. Silica Quartz. The Documentation of the Threshold Limit Values. 4th ed. Cincinnati OH:American Conference of Governmental Industrial Hygienists.
2. ACGIH 1986. Silica Crystalline-Quartz. The Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati OH:American Conference of Governmental Industrial Hygienists.
3. ACGIH 2001. Silica Crystalline-Quartz. The Documentation of the Threshold Limit Values and Biological Exposure Indices. 7th ed. Cincinnati OH:American Conference of Governmental Industrial Hygienists.
4. Respirable crystalline silica dust exposure during concrete finishing (grinding) using hand-held grinders in the construction industry;Akbar-Khanzadeh F;Ann Occup Hyg,2002
5. Neopterin as a new biomarker for the evaluation of occupational exposure to silica;Altindag ZZ;Int Arch Occup Environ Health,2003