Forgotten books, or should we say lost books? The official listing of books at the backcover of the albums by François Schuiten and Benoît Peeters is changing over time. Books appear and and then disappeared for various reasons (stock exhausted, disinterestedness of the author, works out of commerce, deliberate will to make disappear the book etc.).
At the forum Lefranc, Alix, Jhen ... et les autres Raymond made an excellent listing of all the books made by Schuiten and Peeters that are now hard to find.