Hope this is the one you wanted.  Note it is a pdf file.

http://arxiv.org/PS_cache/arxiv/pdf/1107/1107.5728v2.pdf

Good to see the study being discussed.  Thanks for the pointer. 

If only I were more ambitious or even just more focused I might have finished a project I started around November 2008 that turns up many of the same names found at the top of this study's list.  It is why I found the study creditble as well as more than a little incomplete.  It barely covers the major role these institutions play as major owners and market makers in government debt around the world.  They are the bond market that made the Clinton Administration Eisenhower Republicans and James Carville want to be reincarnated as.  They are the money market.

My project was to identify the financial institutions who were (are) the primary dealers of the central banks of the world during 'the fall of 2008'*  Before the fall of Lehman I did not even know the term but after reading the description and disclaimer on the NY Fed's website, I was entranced.  At that time the Fed's Primary Dealers were its Open Market Committee's exclusive counterparties and they were beginning to fall like dominoes.   From the Fed's perspective, the only way it had then of doing anything major was through them.  It was like the it had painted itself into a corner. I think that largely explains why Bernanke had that deer-in-headlights look when he and Paulson were before Congress trying to arrange TARP.  Also, one of the first thing Bernanke's Fed did after things started to settle down was to begin opening other channels and enlisting other counterparties.

I wish I had the resources and wherewithall to finish my project.  Maybe next year.

*a pun borrowed from the NY Fed's Liberty Street blog.