https://stackoverflow.com/questions/18553794/is-it-okay-to-set-title-and-meta-description-in-php-like-this
https://www.lunametrics.com/blog/2013/02/19/php-seo/
https://stackoverflow.com/questions/6113716/getting-meta-title-and-description
https://stackoverflow.com/questions/6113716/getting-meta-title-and-description#comment7091260_6113716
https://stackoverflow.com/questions/13009227/php-how-to-change-title-of-the-page-after-including-header-php

ดึงจากนอกเว็บ
https://stackoverflow.com/questions/3711357/getting-title-and-meta-tags-from-external-website