P. Air-quality-guidelines-for and O. , SO2: summary of risk assessment, World Health Organisation (WHO), 2005.

E. K. Cairncross and J. John, Dynamic Air Pollution Prédiction System (DAPPS) Communicating air pollution exposure: a novel air pollution index system based on the relative risk of mortality associated with exposure to the common urban air pollutants. IUAPPA 13th Annual World Clean Air and Environmental Protection Congress and Exhibition, 2004.

D. Leeuw, . Frank, and W. Mol, Air quality and air quality indices: a world apart? ETC/ACC Technical paper, 2005.