Wikipedia gives you an answer, whereas Amazon delivers the book.
Wikipedia spoon feeds a ready-made response, whereas Amazon offers many points of view. These days my book reading has grown hugely as, whether a book or eBook, I use each book like a stepping stone to another. As I read I form a view on the authors most often cited and invariably, as a result, order the next book. It may be out of print, but is available as an eBook or print on demand, it may be 100 years old, or an ex-library book, or come with a dedication. The learning journey I take I feel is my own.