huh. thanks. so that's the second type listed at wikipedia? or am i confused? perhaps you or he could fix / clarify the wikipedia article? i guess i could but it feels odd to do it third-hand...

I wish I could give you a link to one of Prof. Hicks's published papers on the topic, but I'm having trouble finding one that isn't behind a paywall. This seems like a nice introduction: http://www.math.drexel.edu/~ahicks/papers/physics-today.pdf

If you have access to journals through a university, you could take a look at some of his papers yourself (His website is http://www.math.drexel.edu/~ahicks/). They're easy enough for a sophomore to recreate the results. (I know, because I did for an independent study with Prof. Hicks.)