European power exchanges:

Nord Pool Spot 
EPEX 
GME (Italy)
OPCOM (Romania)
HEnEx (Greece)
TGE (Poland)
OMIE (Spain and Portugal)
OKTE (Slovakia)
OTE (Czech Republic)
HUPX (Hungary)
SOUTHPOOL (Slovenia)
EXAA (Austria)
EPIAS (Turkey)
CROPEX (Croatia)
SEEPEX (Serbia)
ETPA (Netherlands)
NASDAQ
SEMOpx
MEMO (North Macedonia)
ALPEX (Albania)
MEPX (Montenegro)
 
Bulgarian Institutions and organizations:

Ministry of Energy
Energy and Water Regulatory Commission
Bulgarian Energy Holding EAD
Electricity System Operator EAD
 
International Institutions and organizations:

NEMO Committee
EUROPEX
APEX
ACER
ENTSO-E
EURELECTRIC
International Energy Agency
Energy Community