1. “Fundamentals of Molecular Spectroscopy”, Banwell C N (McGraw-Hill, 1983)
2. Infrared Analysis, Inc. (Anaheim, CA, USA) see www.infraredanalysisinc.com
3. US Environmental Protection Agency. See www.epa.gov
4. US National Institute of Standards and Technology. See www.nist.gov
5. “Techniques and Mechanisms in Gas Sensing”, Ed. Moseley P T, Norris J O W and Williams D E, Publ. IOP (1991)