1. National Climatic Data Center. National Center for Environmental Information, Homepage
https://www.ncdc.noaa.gov
. Last accessed on 2019/08/29
2. Pacific Marine Environmental Laboratory Homepage.
https://www.pmel.noaa.gov/aboutpmel
. Last accessed on 2019/08/29
3. Rasmusson EM, Carpenter TH (1982) Variations in tropical sea surface temperature and surface wind fields associated with the southern oscillation/El Niño. Mon Weather Rev 10:354–384
4. Shea D Climate data guide.
https://climatedataguide.ucar.edu
. Last accessed on 2019/08/29
5. Trenberth K & National Center for Atmospheric Research Staff (Eds): The climate data guide: Nino SST Indices (Nino 1 + 2, 3, 3.4, 4; ONI and TNI). Retrieved from
https://climatedataguide.ucar.edu/climate-data/nino-sst-indices-nino-12-3-34-4-oni-and-tni