Debt Capital Markets - Sovereign Debt

Hi all,

So obviously one of the major investment banking functions is underwriting corporate debt offerings (lots of information on this), but I am interested in knowing about groups that specialize in sovereign debt offerings. I know that many banks have well defined public debt divisions that focus on issuing municipal level debt. However, I have had trouble finding much information on sovereign debt offerings and the bankers/analysts that deal with that (i.e. Credit Suisse explicitly mentions they deal with this but offers no more information). Does anyone have any insight into this? Thanks in advance.