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North American Numbering Plan - Wikipedia
List of North American Numbering Plan area codes - Wikipedia
List of North American Numbering Plan area codes
Original North American area codes - Wikipedia
Lists of North American area codes - Wikipedia
Telephone numbering plan - Wikipedia
Category:Area codes in the United States - Wikipedia
North American Numbering Plan - Simple English Wikipedia, …
Telephone numbering plan - Simple English Wikipedia, the free …
United States of America Area Codes / USA Area Code Map / …