ドア郡 (ウィスコンシン州)
↑ Feature Detail Report for: Washington Island. Geographic Names Information System. U.S. Geological Survey. 1980年8月29日.
↑ Historical Weather for Manitowoc, Wisconsin, United States of America. Weatherbase.com.
↑ Door County Cherryland Airport. Federal Aviation Administration. Qtd by AirNav. 2012年5月31日.
↑ Ephraim-Gibraltar Airport. Federal Aviation Administration. Qtd by AirNav. 2012年5月31日.
↑ Washington Island Airport. Federal Aviation Administration. Qtd by AirNav. 2012年5月31日.
↑ Rates, Schedule, and Ferry Information. Washinton Island Ferry Line. 2012年.
↑ The History of Door County Cherries. Orchard Country Winery & Market.
↑ Apple and Cherry Orchards and Farm Markets of Door County. p.1. Door County Visitor Bureau. (PDFファイル)