Who Magazine series overview, in issue 407 (pp26-29). The Discontinuity Guide , which counts the unbroadcast serial Shada , lists this as story number 129. Region 1 DVD releases follow The Discontinuity Guide numbering system. ^ Shaun Lyon et al. (2007-03-31). "The King's Demons" . Outpost Gallifrey . http://gallifreyone.com/episode.php?id=6k . Retrieved 2008-08-30