1: Introduction
2: Airspace sectors
3: Bulgaria Airport Documentation
4.2: ARAD TMA
4.3: Black Sea
4.4: Bucharest
4.5: Napoc TMA
4.6: Procedural
4.7: Other
4.8: Uncontrolled
Here one will find links to websites that are useful to pilots and controllers within the Sofia FIR:
VATSIM
ROVACC
ROVACC Slack
ROVACC Slack registration
VATEUD