private function removeArticles()
{
$journalArticles = $this->em->getRepository('OjsJournalBundle:Article')->findBy(['journal' => $this->journal]);
$this->io->progressStart(count($journalArticles));
foreach ($journalArticles as $article) {
$this->io->progressAdvance();
$this->em->remove($article);
}
$this->em->flush();
}