To find reliable statistics and reports on the open web, use Google to search by keyword and add site:.gov to the search box.
This will limit your search results to information on government websites.
While it's important to evaluate all information sources critically and logically, the information you find on government websites is generally authoritative, credible, and cite-worthy.
If you find a book that you like, you can research how many times it has been cited by other authors with Google Scholar.