Title: Knock, Knock! Who's There? (Sesame Street), Author: Anna Ross
Title: Knock, Knock! Who's There?: A Book of Animal Sounds (Rookie Toddler), Author: Pamela Chanko
Title: Knock Knock Who's There: My First Book Of Knock Knock Jokes, Author: Tad Hills
Title: Knock! Knock!: Ladybird I'm Ready to Read: A Rhythm and Rhyme Storybook, Author: Penguin Random House Children's UK