-[[Google reCAPTCHA を使ってみる(コンタクトフォーム) | Web Design Leaves:http://www.webdesignleaves.com/wp/php/1673/]] -[[GitHub - google/recaptcha: reCAPTCHA is a free service to protect your website from spam and abuse.:https://github.com/google/recaptcha]] -[[Composer:https://getcomposer.org/]] -[[PHP-FIG — PHP Framework Interop Group:http://www.php-fig.org/]]