Ecce you old man, you can turn any text you want into a link so it doesn't ruin the joke. Put these [] around [couldn't resist] and without a space the link in between these () so it's all one long lone. Then it becomes [couldn't resist]/(http://www.amazon.com/Philosophiae-Naturalis-Principia-Mathematica-Latin/dp/1603863796/) , notice the slash in between. When you remove it, it makes couldn't resist.