http://www.energycharter.org/what-we-do/dispute-settlement/investment-dispute-settlement-cases/97-cez-as-v-bulgaria/
http://globalarbitrationreview.com/article/1067298/another-energy-claim-ignites-for-bulgaria (requires subscription)
http://www.iareporter.com/articles/bulgaria-faces-energy-charter-treaty-claim-after-investor-warned-of-harms-due-to-feed-in-tariff-changes-and-renewables-regulation/ (requires subscription)
http://www.cez.cz/edee/content/file-s/pro-investory/informacni-povinnost-emitenta/2016-07/cez-033-2016_en_982l867givyl37pg.pdf