Spencer just had a rough day and needed to rest for a while. He took a nap in the library because it was quiet, that's all. I don't think it's magic fatigue like the others have, but Spencer would know that better than anyone.
Pomeranius Tribb wrote Anatomy of a Puff, but that's the only one in the catalog tailored to specific study. I don't know offhand as far as journal articles and current research are concerned, but I can take a look and come up with a list for you in a day or two. Is it anything to do with the students? Should I make it a priority?