ドア郡 (ウィスコンシン州)
1 2 3 American FactFinder. U.S. Census Bureau. 2011年.
1 2 Door county. Dictionary of Wisconsin History. Wisconsin Historical Society.
↑ A Brief History of Door County, Door County Recruitment for County Administrator. Door County.
↑ Holand, Hjalmar R. History of Door County, Wisconsin. Chapter X. Door County's First Settler. Chicago: The S.J. Clarke Publishing Co. 1917年.
↑ Holand, Chapter XI. An Outline of Door County History.
↑ Belgian-American Research Collection. University of Wisconsin Digital Collections. University of Wisconsin.
↑ Sturgeon Bay and Lake Michigan Ship Canal. The Historical Marker Database. HMdb.org.
1 2 Lyttle, Bethany. High&Low - Door County, Wis.: 'The Cape Cod of the Midwest'. The New York Times. 2008年9月11日.