Airline Codes - Wikipedia | PDF | Naming Conventions | Written Communication
Area codes 920 and 274 - Wikipedia
International Calling Codes - Nations Online Project
List of country calling codes - Wikipedia
Confluence Mobile - UN Statistics Wiki
File:List of country calling codes - Wikipedia.png - Wikipedia
List of dialling codes in the United Kingdom - Wikipedia
Telephone numbers in China - Wikipedia
Telephone numbers in South Africa - Wikipedia
Area codes in the Caribbean - Wikipedia
Which country's code is +23? - Quora
Area codes 410, 443, and 667 - Wikipedia
Telephone numbers in Iran - Wikipedia
Telephone numbers in Cyprus - Wikipedia
Telephone numbers in Italy - Wikipedia
Area code 409 - Wikipedia
Telephone numbers in Greece - Wikipedia
Telephone numbers in Spain - Wikipedia
List of Georgia area codes - Wikipedia
Telephone numbers in Germany - Wikipedia
3 Ways to Make International Calls from Thailand - wikiHow
Telephone numbers in Australia - Wikipedia
List of dialling codes in Brazil - Wikipedia
