Bart Simpson's Treehouse of Horror (1999–2011) — book series in order

Manyebook

Bart Simpson's Treehouse of Horror (1999)
Bart Simpson's Treehouse of Horror (2001)
The Simpsons Treehouse of Horror (2003)
The Simpsons Treehouse of Horror (2006)
The Simpsons Treehouse of Horror (2008)
The Simpsons Treehouse of Horror (2011)