http://globalarbitrationreview.com/news/article/33278/bolivia-pays-highest-ever-settlement-foreign-investor/ (requires subscription)
http://in.reuters.com/article/2014/12/18/bolivia-energy-idINL1N0U21ZC20141218
http://www.iisd.org/itn/2010/05/11/pan-american-energy-takes-bolivia-to-icsid-over-nationalization-of-chaco-petroleum/
https://books.google.ch/books?id=RbQq8dQtsQ0C&pg=PA72&lpg=PA72&dq=chaco+pan+american+bolivia&source=bl&ots=8q3ufs2zMa&sig=Mwk4iPcE5utofTL67PdcfIG0ewE&hl=en&sa=X&ei=4Ar3VLSmKIHXONnEgLAG&ved=0CEAQ6AEwBg#v=onepage&q=chaco%20pan%20american%20bolivia&f=false