* stackoverflow.com/questions/46913744/wordpress-child-theme-of-a-child-theme
* neliosoftware.com/blog/grandchild-theme-customizing-child-themes/?nab=0&utm_referrer=https%3A%2F%2Fneliosoftware.com%2Fblog%2Fgrandchild-theme-customizing-child-themes%2F
* www.wp-code.com/wordpress-snippets/wordpress-grandchildren-themes/
* docs.appthemes.com/tutorials/creating-grandchild-themes/