Just go here:
http://www.hypertrophy-research.com/page9.html and you'll see several of the recent studies. That's the first one they have listed.
Now these are just studies of course but I've read over them and in certainly paints a picture....
Some of the things I like from them cuz they back me and others here up is: UNTRAINED individuals get maximum strength gains from working a muscle group three times a week (low volume)
(what's that IA?). Trained individuals do better with 2 times a week. One set only really works for good strength gains in untrained and as training progresses more volume (more sets) is needed. (what's that Hittite's?).
However, these are meta-analyses and there is another paper criticizing these four recent ones for not following the proper procedures and saying that the data did not support their conclusions. It's very difficult to compare many studies of different design so nothing is ever cut and dry in these things. We have to go by what we think and what works best for us but we'll see what develops on the horizon. It's nice to have science confirm or discard certain practices though.