conceptual artists' books?

Would a conceptual artist's book be an "altered book"? Or a "found book"? Or perhaps a book taken from one's shelf, with only the title page altered or replaced in favor of one that credits the artist who is committing the act of appropriation? What about taking an existing book, cutting out all of the pages, printing something else on the pages over the existing print & possibly images, then re-binding it in either a similar or divergent manner from the original? What about taking an existing book, pasting or sewing it along formerly openable sides so that the book is unopenable, placing it in another container that credits the artist/appropriator? Is something like Kenneth Goldsmith's Day, in which the author has retyped an entire day's issue of the New York Times and re-framed it as a book, as much a conceptual artist's book as a piece of conceptual writing? What other possibilities might there be? Are there particular interventions into existing works that are most useful in thinking of artist's books? I welcome your comments, and depending on what comes of them, I might try to create an exhibition of conceptual artist's books. I have no illusions that works such as I have proposed, or that others might propose, are anything new, i.e. such works have been made in the field of artis's books for years, even decades. Is it anything new to think of such work as "conceptual"?