World's Finest Comics
Virtually every issue featured DC's two leading superheroes , Superman and Batman , with the earliest issues also featuring Batman's sidekick , Robin . 
<triplet> Superman <subj> superhero <obj> instance of <triplet> Batman <subj> superhero <obj> instance of <triplet> Robin <subj> superhero <obj> instance of <subj> Batman <obj> sidekick of