How to Configure Contact Form 7 for Your WordPress Site
Consider Using Localized Input Masks for 'Phone' and Other Restricted Inputs (64% Aren't Taking Advantage of Input Masking) – Articles – Baymard Institute
How to Style Contact Form 7 Forms in WordPress
How to Create Input Masks for Your Site's Forms (With Examples)
How to Create Input Masks for Your Site's Forms (With Examples)
Add Custom Fields to Contact Form 7 and Stay in Touch with Clients
Ninja Forms Contact Form – The Drag and Drop Form Builder for WordPress – WordPress plugin | WordPress.org
How to Use Input Mask in Your Contact Form (Examples) - Ninja Forms
Contact Form 7 Tutorial - Specific Instructions - Help for WordPress