The Comprehensive 20 Year Simpsons Episode Guide

The Comprehensive 20 Year Simpsons Episode Guide is a The Simpsons reference book.

History
After the Simpson family run into the living room, Moe shouts "happy 500th episode" and a celebration starts. Lisa then stops the celebration while reading this book and works out that this is episode 499, not 500.

Behind the Laughter
The book is a parody of the real-life The Simpsons guide book, Simpsons World The Ultimate Episode Guide: Seasons 1-20 in both appearance and name.