The following is a list of sources used in the creation of Wikipedia articles on various geographic topics and locations, such as cities, counties, states, and countries. These sources are cited within the thousands of articles which link to this page.
2 The United States Census Bureau's 2000 census data. Much of the geographic and demographic information for the U.S. states, counties, and cities came from the data on the site. The data are not totally accurate due to various polling errors, but they are an approximate estimate. See the Bureau's website for more information. The data were used for the following topics: geographic areas (total, land, and water), population and housing unit densities, demographic spreads across race, age, sex, and income. The data are indexed by state, county, and place FIPS codes. See also Race (US Census) for a list of the definition of race according to the U.S. Census Bureau. Source: http://www.census.gov http://factfinder.census.gov
3 The Geographic Names Information System developed by the United States Geological Survey. The data contain information on a wide range of geographic features such as populated places, rivers, mountains, certain buildings, etc. The data provided include geographic coordinates, elevation at the point, population (if applicable), and the FIPS codes for the state and county containing the feature (but not the feature itself). Source: http://geonames.usgs.gov/
The following is a list of resources useful for a specific subset of the geographic topics. These resources can be used as a future source for additional information on that specific topic.
Statistics Canada. Data from the most recent census on cities across Canada is available here.
ISTAT, the official census arm of the Italian government, provides detailed demographic breakdowns and aggregate population figures for all the comuni, provinces and regions: currently the latest census year available is 2003.
Guida ai Comuni d' Italia (Metropolis), an unofficial site that reproduces ISTAT data from other census years, and other information from official sources (surface areas of the comuni, names of frazioni and localitÓ, etc.)
Italian Wikipedia's "WikiProject Comuni" will also be useful.