This issue is a variant of Superman (DC, 1987 series) #16 [Direct].
There exist further variants.
On-sale date from Amazing Heroes #131.
Letters from readers - William Waldman, Johny Q., Kiril Kundurazieff, Jeff Mitchell, Fred L. Cain, Ann C.H. Brachwitz, David Metz, Mark Billian, Marc Ouellette, Nicholas J. Taylor and Roger D. Case.