Locating evidence of impact for books and book chapters can be more challenging than traditional journal articles.
Some recommended resources include:
Google Scholar includes citation data for most books from scholarly presses. Here's an example:
Web of Science includes Science Book Index and Social Science and Humanities Book Index, 2005-current. From the search screen, click on 'more settings' and un-click everything except the book index you'd like to search. NOTE: Not all books are included.