That being said, the effect of all those references (on me anyway) was more to highlight the weakness of the research literature than to make a convincing case. But that's not Glass' fault. He does a great job of reporting what the literature says.
It's quite concise (224 pages), but it's chock full of quite excellent advice. Each one of these points (and many others) is fleshed out in a separate chapter that gives a good deal of background, clarification, and supporting evidence.