Having a full library of Google Play Books at your disposal would normally require obscene amounts of time and money to purchase all of them, but if you're looking for a specific passage, Google's new AI-based natural language search experiment called "Talk To Books" may be just what you need. The project lets you put in a query in full, natural sentences, in much the same way that you would talk to a Google Home unit. The kicker here is that you're actually asking a question of the books themselves, which means that the queries can take on a more personal and specific quality.
Some of the sample phrases provided by Google on the Talk to Books page are "What smell brings back great memories?" and "What is fun about computer programming?" Essentially, the point of the project is to allow people to ask the database the kind of questions that they would normally have to sort through tons of books to find the answers to, and instantly find out which books to find those answers in. The system is far from perfect, but as with most user-addressable Google AI projects, it grows smarter with continued use as it learns more about each user and the way that people collectively frame questions and what results they favor. You can play around with it and ask it just about any question, and it will combine natural language processing with conventional search techniques to try to surface a set of results that can be reasonably expected to give you a satisfactory answer. Unfortunately, in most cases, the passage that gives you what you want will be outside of the purview of a book's preview, forcing you to buy the book in order to get the answer or materials you seek. Even so, queries that would normally make some AI programs scoff such as extremely specific or nonsensical ones, can produce interesting results.
This project is part of Google's ongoing effort to infuse AI concepts into all of its products and services. In this particular case, there is a bit of profiteering mixed in with the public service; by allowing people to narrow down the list of books they need to pore through to find out, view, or understand the object of a particular query, the people doing the searching are just a bit more likely than normal to buy a book from Google Play Books, if they find it to contain something satisfactory to their query.