Superman Volume 2 Issue 7

Whilst flicking through an issue of Superman, the Twelfth Doctor scribbled a pair of glasses onto the titular character in one panel, to demonstrate to Grant Gordon that he was secretly Clark Kent. (TV: The Return of Doctor Mysterio)

Behind the scenes
The comic, which is unidentified in the story, is issue 7 of DC's second Superman comic series that ran from 1987 to 2006. The way in which the scenes of the Doctor reading it are ordered make it look as if the panel appears within the same publication as the series of pages that are actually from issue 19 of the same series.