Economic theory / papers on sovereign debt?
Carmen Reinhart from Harvard Kennedy School works extensively on these questions. She has a recent paper forthcoming  in the Journal of the European Economic Association, 2016, entitled "Sovereign Debt Relief and its Aftermath" with Christoph Trebesch. They study sovereign debt relief in a long-term perspective, using two distinct samples: 1920-1939, and 1978-2010. They published a short Vox-CEPR column on this research.

In their book, with Kenneth Rogoff, "This time is different" they address this question. They have also other interesting and good papers:


Reinhart, Carmen, and Kenneth Rogoff. "Dealing with Debt." Journal of International Economics 96 (July 2015): S43-S55. 
Reinhart, Carmen, and Kenneth Rogoff. "Financial and Sovereign Debt
Crises: Some Lessons Learned and Those Forgotten." Financial Crises:
Causes, Consequences, and Policy Responses. Ed. Stijn Claessens, M.
Ayhan Kose, Luc Laeven, and Fabian Valencia. International Monetary
Fund, 2014.


Check also:


Reinhart, Carmen M., and M. Belen Sbrancia. "The Liquidation of
Government Debt." Economic Policy 30.82 (March 2015): 291-333.