List of country calling codes - Wikipedia
formatting - What is the preferred way to format phone numbers when supporting international ones? - User Experience Stack Exchange
What is E.164? | Twilio
How to Dial International Numbers: 2 Step-by-Step Methods
Get Local Business Phone Numbers in 70+ Countries | JustCall
Dial International Phone Numbers from iPhone the Easy Way Using the +Plus Prefix | OSXDaily
How to Dial Abroad Without Making Mistakes: International Phone Number Format & Examples
International Phone Numbers for Businesses| CircleLoop
Understanding International Phone Number Terminology | by Khoi Pham | Medium
Phone Number By Country | PCF Gallery
Local Phone Numbers in the U.S. and Worldwide | net2phone
The Format of International Telephone Numbers
International Calling Codes - Nations Online Project
International Phone Numbers: A Must in Global Businesses
International Phone Number | Phone System | Freshcaller (formerly Freshcaller)
Guide on How to Format International Phone Numbers - IDT Express
Top 10 Advantages of International Phone Number That are Most Helpful
How to give a US phone number internationally - Quora
International Phone Numbers - Be Open Worldwide | Channels
International phone numbers — formatting and validation for phone numbers based on country rules — Fluid Checkout
How To Add International Phone Numbers On WhatsApp iPhone - YouTube
How to enter a phone number in international format? - AutoForward SMS
International Phone Numbers - How to Get or Buy One - MightyCall
