Difficult Logic Puzzles for Smart Kids: 150 Brainteasers and Puzzles the Whole Family will Love

Difficult Logic Puzzles for Smart Kids: 150 Brainteasers and Puzzles the Whole Family will Love

Difficult Riddles For Smart Kids: 300 Difficult Riddles And Brain Teasers Families Will Love (Thinking Books for Kids)

Math Riddles For Smart Kids: Math Riddles And Brain Teasers That Kids And Families Will love (Thinking Books for Kids)