Science Conan: Unraveling the Mysteries Around Us Mysteries of Disaster Prevention Mysteries of Space and Gravity Mysteries of Ninjas Mysteries of Food Mysteries of Elements Total of 6 books These are not sold separately. There is some yellowing, staining, soiling, scratches, and creases due to aging, but the contents can be read without any problems. I have checked the books overall, but I have not checked each page in detail. Please forgive any oversights as I am a non-professional inspector. Please refrain from purchasing if you are looking for perfection, as these are used items stored at home. I am not accepting price negotiations. Instant purchase is OK.