Bob Phillips 
Good Clean Knock-Knock Jokes for Kids [EPUB ebook] 

What can steer a parent toward insanity faster than the phrase "Are we there yet?"…the words "Knock, Knock, " of course. Bob Phillips, comic genius, has mastered a gathering of knock, knock jokes that will have kids laughing hysterically–and parents just plain hysterical–but a family that knock, knocks together, grows together. Knock, Knock Who’s There? Olive. Olive who? Olive to tell knock-knock jokes. Hours of entertainment in one simple resource is the best deal in town.