Set of two books. The blue book has one small stain on the back cover, but otherwise, they have only been read once and have no noticeable stains or scratches. - Author: Daisuke Muramatsu - Title: Quantum Mechanical Practice Techniques - Title: How to Live Connected to the Zero-Point Field Where Everything is Prepared - ISBN: 978-4-7991-0367-0 - ISBN: 978-4-7991-1500-0 Thank you for looking.