https://bootstrapious.com/p/how-to-build-a-working-bootstrap-contact-form

https://phppot.com/php/bootstrap-contact-form-with-javascript-validation-and-php/

https://codesolution.co.in/detail/post/bootstrap-form-validation-in-the-html

https://www.jquery-az.com/free-bootstrap-registration-create-account-form-3-code-snippets/

https://codepen.io/nj_codes/pen/wRLzGX

https://www.javatpoint.com/confirm-password-validation-in-javascript