LEETSDALE (AP) - A Pennsylvania school district is apologizing after quotes from Adolf Hitler, Josef Stalin and an Islamic State terrorist leader were printed in the graduating class section of this year's high school yearbook.

Quaker Valley School District officials tell the Pittsburgh Tribune-Review that, "Though the content of the quotes was reviewed thoroughly, the attributions clearly were not."The Hitler quote is "Words build bridges into unexplored regions" while Stalin's statement is more menacing: "Ideas are more powerful than guns. We would not let our enemies have guns, so why would we let them have ideas?"The third quote is from Abu Bakr al-Baghdadi: "Be just: the unjust never prosper. Be valiant. Keep you word, even to your enemies."Students can get a refund on the books, or stickers to cover up the quotes.