1. World Health Organization (WHO) guidelines for coastal and fresh waters: Italian translation by the Society of Hygiene, Preventive Medicine and Public Health (SItI) working group “Movement Sciences for Health”;Napoli;Ig. Sanità Pubbl.,2010
2. Guidelines for safe recreational water environments;WHO,2006
3. Guidance on water quality for heated spas;Broadbent,1996
4. Management of spa pools: controlling the risk of infection;Newbold,2006