For example, the number of people licensed to offer an electronic book is small and they don't understand exactly what is needed. According to Rio (2003), “most e-book vendors do not appear to understand the needs of libraries or are not properly licensed” (p.89). Those who supply books, other than producers, do not need a license to sell books and do not have to have experience selling books. Furthermore, paper books are available even in the most deprived places on earth, but e-books are not. According to Rio (2003), “dedicated readers are not widely available worldwide” (p.89). Furthermore, e-books present a problem known as "copy right", while this problem is not found in paper books. According to Rio (2003), “the right of resale is different from when a book is purchased…e-book distributors reassure publishers of their intellectual property rights by providing a very controlled user interface, without making it too cumbersome and cumbersome for users” (p.89). Due to copying rights, the content of the electronic version is not always printable and this is not a drawback when using paper