Science Picture Book Series, Complete Set of 10 Volumes. Volumes 1-10 - Series Title: Which is Stronger!? Praying Mantis vs. Crayfish - Number of Volumes: 10 - Publisher: Kadokawa Shoten - Target Age: Elementary School Students - Condition: Used Thank you for viewing. I am selling these because my child no longer reads them. There are no writings, but there are some scratches and folds. Thank you for your understanding.