1. American Industrial Hygiene Association 1991 Respiratory Protection: a Manual and Guideline , 2nd ed C. E. Colton , L. R. Birkner L. M. Brosseau
2. American National Standards Institute 1992 American National Standard for Respirator Protection (ANSI Z88.2).
3. American Conference of Governmental Industrial Hygienists 2004 2004 TLVs and BEIs