Batman: Once Upon a Time…, tribute to Charles M. Schulz‘ Peanuts (adaptation of Snoopy’s novel), by Len Wein (USA) & Walter Simonson (USA) in: Detective Comics Vol. 1 #500, DC Comics, USA, March 1981.
Between “August and September of 1969, Charles M. Schulz devoted a few weeks’ worth of strips to Snoopy’s novel.” In 1981, Len Wein wrote a Batman “two-pager with art by the great Walt Simonson. The story has no dialogue. It only has captions. The captions? All lines from the aforementioned Snoopy novel!!” Brian Cronin, Comic Book Resources, 2010.
Peanuts strips: Copyright ©1969 United Feature Syndicate/Charles M. Schulz
Batman story: Copyright ©1981 DC Comics