When creating “Knacka på”, Anna-Clara focused on the actual turning of the pages in a book. That pages can be opened and closed like “doors”! Had anyone ever made full use of the act of browsing? The child/ reader, who is the main character, soon learns to knock on every door and open them in optional order until he/she exits the house. Anna-Clara created an early, interactive picture book! The book has a permanent place on Sweden’s top ten list. The whole series consist of four wonderfully ingenious interactive picture books for the very young children. They have basic, but rhythmic two-word sentences that mimics early language.

This unique book was published in 1992 and has sold around 500 000 copies in Sweden and nearly as many internationally (with around 300 000 in Korea and 100 000 in Germany topping the lists) and it has been translated into 20 languages.