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geonames.usgs.gov/pls/gnispublic/f?p=gnispq:3:::NO::P3_FID:406048
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en.wikipedia.org/wiki/Chicago_Ridge,_Illinois (22 Aug 2010)
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www.chicagoridge.org/ (28 Jul 2010)
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geonames.usgs.gov/pls/gnispublic/f?p=gnispq:3:::NO::P3_FID:2397620
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idaillinois.org/cdm/landingpage/collection/crpl (23 Feb 2013)