Legionella.org. About the disease. http://legionella.org/about-the-disease/what-is-legionnaires-disease/. Accessed June 2016.
Centers for Disease Control and Prevention. Legionella (Legionnaires' Disease and Pontiac Fever). http://www.cdc.gov/legionella/index.html. Updated January 15, 2016. Accessed May 2016.
United States Department of Labor. Occupational Health and Safety Administration. Legionnaires' disease. https://www.osha.gov/SLTC/legionnairesdisease/index.html (no date). Accessed July 9, 2013.