1. ACGIH, 1992, American Conference of Governmental Industrial Hygienists, Threshold Limit Values and Biological Exposure Indices, Cincinnati, OH, USA.
2. ACGIH, 1996, TLVs and BEIs. Threshold Limit Values for chemical substances and physical agents. Biological Exposure Indices. American Conference of Governmental Industrial Hygienists, Cincinnati, OH, USA, ISBN 1-882417-13-5.
3. ACGIH, 1998, TLVs and BEIs. Threshold Limit Values for chemical substances and physical agents. Biological Exposure Indices. American Conference of Governmental Industrial Hygienists, Cincinnati, OH, USA, ISBN 1-88-2417-23-2.