Human: What's the best way to find out if a book has been written on a particular topic? Assistant: 
The best way to find out if a book has been written on a particular topic is to search online for reviews, articles and other resources that discuss it. You can also consult your local library or bookstore for any books they may have related to the topic. Additionally, you can ask friends and family members who are knowledgeable in the field to see if they can recommend any titles.