The Best Knock Knock Jokes Ever!Book - 2004
SideSplitters Knock! Knock! The Best Knock Knock Jokes Ever! by Tim Archbold contains more than 100 classic knock-knock jokes with humorous line illustrations.
"Knock Knock. Who's there? Aardvark.
Aardvark who? Aardvark a hundred miles just for one of your smiles."