http://www.aoml.noaa.gov/hrd/tcfaq/A11.html National Oceanic and Atmospheric Administration/Frequently Asked Questions: «What is the "eye"? How is it formed and maintained? What is the "eyewall"? What are "spiral bands"?»
Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division. "Frequently Asked Questions: How do tropical cyclones form?". National Oceanic and Atmospheric Administration. http://www.aoml.noaa.gov/hrd/tcfaq/A15.html. Retrieved 2006-07-26.
Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division. "Frequently Asked Questions: Why do tropical cyclones require 80 °F (27 °C) ocean temperatures to form?". National Oceanic and Atmospheric Administration. http://www.aoml.noaa.gov/hrd/tcfaq/A16.html. Retrieved 2006-07-25.
Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division. "Frequently Asked Questions: When is hurricane season?". National Oceanic and Atmospheric Administration. http://www.aoml.noaa.gov/hrd/tcfaq/G1.html. Retrieved 2006-07-25.