what are artist´s books?

Artists' books are works of art realized in the form of a book. They are often published in small editions, though sometimes they are produced as one-of-a-kind objects referred to as "uniques".
Artists' books have employed a wide range of forms, including scrolls, fold-outs, concertinas or loose items contained in a box as well as bound printed sheet. Artists have been active in printing and book production for centuries, but the artist's book is primarily a late 20th century form.

"Artists' books are books or book-like objects over the final appearance of which an artist has had a high degree of control; where the book is intended as a work of art in itself." Stephen Bury