txt_file = models.FileField(_('TXT file'), upload_to=book_upload_path('txt'), blank=True)
mp3_file = models.FileField(_('MP3 file'), upload_to=book_upload_path('mp3'), blank=True)
ogg_file = models.FileField(_('OGG file'), upload_to=book_upload_path('ogg'), blank=True)
txt_file = models.FileField(_('TXT file'), upload_to=book_upload_path('txt'), blank=True)
mp3_file = models.FileField(_('MP3 file'), upload_to=book_upload_path('mp3'), blank=True)
ogg_file = models.FileField(_('OGG file'), upload_to=book_upload_path('ogg'), blank=True)