-- category -> talk pages -> main pages -> links

​

SELECT pagelinks.pl_title

FROM page talkpage

​

INNER JOIN categorylinks ON talkpage.page_id = categorylinks.cl_from

INNER JOIN page mainpage ON mainpage.page_title = talkpage.page_title

INNER JOIN pagelinks ON mainpage.page_id = pagelinks.pl_from

​

WHERE categorylinks.cl_to = "FL-Class_Catholicism_articles"

AND pl_namespace = 0 AND mainpage.page_namespace = 0 AND talkpage.page_namespace = 1

AND pl_title NOT IN (SELECT page_title FROM page WHERE page.page_namespace = 0)