Retrieved March 16, 2015. "About Our GreatLakes: Tour". National Oceanic and Atmospheric Administration (NOAA) - GreatLakes Environmental Research Laboratory
International Lake Superior Board of Control EPA's GreatLakes Atlas EPA's GreatLakes Atlas Factsheet #1 GreatLakes Coast Watch Archived 2008-05-11 ವೇಬ್ಯಾಕ್ ಮೆಷಿನ್