Supplying an ISBN (and, optionally, a Title) will display a cover image of the relevant book with a link to that book’s page on Google Books using the Google Books API. Using the Widget you can choose whether to: Pad the Image (selected by default, uses internal CSS) Display a Box-Shadow (selected by default, uses internal CSS) Choose Alternate Google Country (defaults to “Worldwide”) as well as Decide whether you would like to use a Title Define the ISBN-10 or ISBN-13 of the book.