Andrew Hunt and David Thomas (Addison-Wesley, 1999) (Images copyright: The Pragmatic Programmers, LLC, https://pragprog.com/book/tpp/the-pragmatic-programmer Andy Hunt (CC BY SA), https://en.wikipedia.org/wiki/File:Andy_Hunt_programmer.jpg James Davidson (CC BY 2.0), http://www.flickr.com/photos/x180/92261484/in/set-72057594055298824/)