links.append("<a href='%s'>%s</a>" % (
reverse('download_zip_mp3', args=[book.slug]), BookMedia.formats['mp3'].name))
if book.has_media('ogg'):
links.append("<a href='%s'>%s</a>" % (
reverse('download_zip_mp3', args=[book.slug]), BookMedia.formats['mp3'].name))
if book.has_media('ogg'):