2017
Asthma Respiratory Foundation NZ
https://www.asthmafoundation.org.nz/your-health/living-with-asthma/common-asthma-triggers 
https://data.cityofnewyork.us/Environment/2015-Street-Tree-Census-Tree-Data/uvpi-gqnh/data 
https://www.health.ny.gov/statistics/ny_asthma/hosp/zipcode/map.htm