El Extra%c3%b1o Mundo De Jack Castellano Archive.org ◆

Wait, maybe there's a mistake in the title. The user wrote "el extraño mundo de Jack" which translates to "Jack's Strange World," and the author's name is Castellano. If I search for that exact title, perhaps the book is part of a series used in language courses. I should confirm if this book is part of a curriculum. If it's in the public domain on archive.org, it might be older, but the author might be a Spanish educator or author.