Much time is wasted writing out quotes that you find. However, with Google books you can copy and paste your quotes. (Not all books are available, but many are.) What I usually do is simply go to the advanced search and then type the first 5-10 words of the quote. If the book comes up, great, I have not wasted time copying it. Here is how it is done.
Some of Google’s full view books can now be seen in a plain text version, additional to the existing images of text. This will allow you to copy the text for personal use, or to create a website of it, or have it be read by a screen reader, or do anything else you want (commercial and non-commercial). To search for full view books, use the advanced search page of Google Books and check the “full view” option. Now when you’re in the book view of a result, click the “view plain text” link at the top right. (Not all full view books were showing this link when I tried.)