Encyclopedia of the Biosphere Humans in the World's Ecosystems 11 Volume Set 

Hardcover 

Gale Group 2000 

Ex-library with standard stickers, stamps and library markings. Bindings are tight. Books show shelf wear and light creasing on the covers and corners. Most likely the pages are clean, as we look through each book twice before we sell it. But, we are human, so there may be very limited underlining, or notes that we missed, but all words are readable.