SELECT DISTINCT

  pg1.page_title

FROM page AS pg1

LEFT JOIN pagelinks

ON pl_from = pg1.page_id

WHERE pg1.page_namespace = 4

AND pg1.page_is_redirect = 0

AND pg1.page_title NOT LIKE "%/%"

AND (SELECT

       COUNT(*)

     FROM page AS pg2

     LEFT JOIN pagelinks AS pltmp

     ON pg2.page_id = pltmp.pl_from

     WHERE pltmp.pl_title = pg1.page_title

     AND pltmp.pl_namespace = pg1.page_namespace

     AND pg2.page_namespace = 4) = 0

LIMIT 1000;