john green is a genius because he creates books
and then he quotes those books
in his books
So does JK Rowling.
JK ROWLING ISNT THE ONLY AUTHOR ALIVE YOU KNOW
Same with Dean Koontz, who then produced said book in limited quantities. Expect to pay, at minimum, $300 for a print copy of The Book of Counted Sorrows.
You could probably find an example of this technique being used by a living author in virtually every genre!