My girlfriend is going to be a new 5th-grade teacher and she is using turtles as her classroom decorating theme. She wants to bring in my russian tortoise for a day or two for a science lesson at some point. I suggested the russian, since he is extremely friendly and careless while my box turtles would surely HATE the children.

Anyway, she wants a book on tortoises for her classroom that is not intended for small children, yet is not something a PhD would use. A good in-between book would be great! Do you have any suggestions for a title and author?