Thanks for the heads up Chen Munn! It looks like there have been some changes in their website. Here is a pdf, and it’s been updated within the course too.
Also the link provided in Further readings from Whitney Hess, Pleasure & Pain (https://whitneyhess.com/blog/2009/11/23/so-you-wanna-be-a-userexperience-designer-step-2-guiding-principles/) is responding with “Not found, error 404: The page you are looking for no longer exists. Perhaps you can return back to the site’s homepage and see if you can find what you are looking for. Or, you can try finding it by using the search form below.” error.