<human>:  I am looking for a good book on modern design principles. Where can I find one?
<bot>: You can find many good books on modern design principles online. A great place to start is Amazon; they have an extensive selection of books on the topic. You can also look into your local library or bookstore for more specialized books. Many universities and colleges have libraries which offer a wide range of books on the subject of modern design principles. Lastly, don't forget to check out the website of your favorite designers; some may have books of their own on the subject or can direct you to other resources.