Columbia subject headings:
Graphic novels.
September 11 Terrorist Attacks, 2001--Comic books, strips, etc.
Terrorism--United States--Comic books, strips, etc.
Harvard subject headings:
Cartoonists--United States--Comic books, strips, etc.
Graphic novels
September 11 Terrorist Attacks, 2001--Personal narratives--Comic books, strips, etc.
Terrorism--United States--Personal narratives--Comic books, strips, etc.
Princeton subject headings: