The books are written by various authors and published by different companies in the United States, in English language and different formats (hardcover and paperback). The collection includes nonfiction books for adults, covering different genres and topics, such as history, science, literature, and more. None of the books have any ex libris or personalization, and they are not signed by the authors. This is a rare opportunity to own a valuable and diverse set of books that can enrich your knowledge and inspire your curiosity.