https://www.w3schools.com/howto/howto_css_login_form.asp
http://www.devmedia.com.br/criando-sessao-para-login-no-php/27347
http://blog.thiagobelem.net/criando-um-sistema-de-login-com-php-e-mysql
http://pt.wikihow.com/Criar-um-Script-de-Login-Seguro-em-PHP-e-MySQL
https://www.tutorialspoint.com/php/php_mysql_login.htmhttps://www.formget.com/login-form-in-php/…
http://novojeitonerd.blogspot.com/2017/05/desenvolvimento-de-sistema-login-e.html
https://thisinterestsme.com/php-user-registration-form/
https://programacion.net/articulo/sistema_de_login_php_con_pdo_1467
http://www.mitrajit.com/php-login-pdo-connection/
https://thisinterestsme.com/php-user-registration-form/
https://programacion.net/articulo/sistema_de_login_php_con_pdo_1467
http://www.mitrajit.com/php-login-pdo-connection/
https://forum.imasters.com.br/topic/557686-trabalhando-com-criptografia-de-login-com-md5/
http://php.net/manual/en/session.security.php
https://phpdelusions.net/sql_injection
// Leituras complementares
http://php.net/manual/en/security.php
http://stackoverflow.com/users/2224584/scott-arciszewski
https://paragonie.com/blog
https://phpdelusions.net/