"Steven Rothman Collection of Comics, Cartoons, and Graphic Novels (University of Pennsylvania)" . . . "Comic books, strips, etc" . . . . . "Comics (Graphic works)" . . . . . . . "X-Men : Endangered species" . . . "Graphic novels" . . "Endangered species" . "X-Men : endangered species" . . . . . . . . . . "Superhero comic books, strips, etc" . . . . "CHR 2008." . . . . "PRO Rothman, Steven D. (donor)" . . "Comics Collection (University of Pennsylvania)" . . "X-Men (Fictitious characters) Comic books, strips, etc." . .