I don't have the original one on hand. The research I encountered was done at the University of Victoria back in the 1980s, and I learned about it while I was a student there.

However I just looked at http://en.wikipedia.org/wiki/Paper_cup#Environmental_impact which has the comment, Paper cups may consume more non-renewable resources than cups made of polystyrene foam (whose only significant effluent is pentane). which includes two citations for the fact.

My father works in recycling. You can recycle styrofoam, but all you can make out of it is packing peanuts. Styrofoam cups aren't exactly a sustainable solution.

Toronto does take styrofoam in it's recycling program now. Though I've never seen that done anywhere else...