• ---. Overviews and Factsheets, US Environmental Protection Agency (EPA), Office of Air and Radiation (OAR), 5 June 2015, https://www.epa.gov/ground-level-ozone-pollution/health-effects-ozone-pollution.
• Ecosystem Effects of Ozone Pollution: Ground-Level Ozone Pollution. Overviews and Factsheets, US Environmental Protection Agency (EPA), Office of Air and Radiation (OAR), 11 June 2015, https://www.epa.gov/ground-level-ozone-pollution/ecosystem-effects-ozone-pollution.
• Gohd, Chelsea. “Ozone Pollution Levels Have Increased over the Past 20 Years, Study Finds”. Space.Com, 1 Sept. 2020, https://www.space.com/ozone-pollution-increase-in-northern-hemisphere.html.
• Ground-Level Ozone Basics. Overviews and Factsheets, US Environmental Protection Agency (EPA), Office of Air and Radiation (OAR), 29 May 2015, https://www.epa.gov/ground-level-ozone-pollution/ground-level-ozone-basics.
• Ozone Effects on Plants - Air. U.S National Parks Service, https://www.nps.gov/subjects/air/nature-ozone.htm. Accessed 29 Dec. 2021.
• “Tropospheric Ozone”. Climate & Clean Air Coalition, 2015, https://www.ccacoalition.org/en/slcps/tropospheric-ozone.