My newest book, Museum Rhetoric, is now available from the Penn State University Press. It is available from their website, with a 30% discount if you use the code EW17: https://www.psupress.org/books/titles/978-0-271-07903-5.html
And it is available from Amazon in both hardcover and a nicely-priced Kindle version: https://www.amazon.com/Museum-Rhetoric-Building-Identity-Transdisciplinary/dp/0271079037/ref=sr_1_1?ie=UTF8&qid=1515365781&sr=8-1&keywords=museum+rhetoric