I have installed SEO-Internal-Links plugin at http://wordpress.org/extend/plugins/seo-internal-links/, and activated it after installation.
But I do not yet see linked keywords when I visit the site.
As the document says, I have also added define(ENABLE_CACHE, true); in the first line of wp-config.php.
Still no luck. The keywords have not been automatically linked to each other.
ENABLE_CACHE? – Max Yudin Feb 21 at 8:40