Internet Country Codes - An alphabetic list of the two-letter letter country codes used as internet top level domains, with the English-language country names. - http://www.web-l.com/country-codes/
USPS ICL to ISO 3166 Mapping - Mapping of United States Postal Service Index of Countries and Localities to ISO 3166 codes. - http://www.25thandclement.com/~william/USPS_ICL.html
ISO 3166 - Code lists and updates, from the official ISO site. - http://www.iso.ch/iso/en/prods-services/iso3166ma/index.html
A three-part standard - ISO 3166 - describes the respective functions of the standard's three parts. - http://www.din.de/gremien/nas/nabd/iso3166ma/a3ptnorm.html
ISO 3166 Maintenance Agency (ISO 3166/MA) - Page of the organization which maintains the ISO 3166 list of country codes. Downloadable list of the two letter country codes and French or English country names. - http://www.din.de/gremien/nas/nabd/iso3166ma/