CREATE TABLE table_8581 ("DVD title" CLOB, "Season" CLOB, "Aspect ratio" CLOB, "Episode count" FLOAT, "Time length" CLOB, "Release date" CLOB)

What is the release date for Ben 10: Alien Force Volume 9 on DVD?
SELECT "Release date" FROM table_8581 WHERE "DVD title" = 'ben 10: alien force volume 9'
SELECT "Release date" FROM "table_8581" WHERE "DVD title" = 'ben 10: alien force volume 9'