чиста
- Aresgas AD
- Avtometan Ltd.
- Baros Ltd.
- Bulgartransgaz EAD
- Citygas Bulgaria ЕAD
- CNG Maritza Ltd.
- Gastechnika Ltd.
- Gastrade Sliven Ltd.
- Generix Parners Ltd.
- Komekes AD
- Mega Electronics Ltd.
- Overgas Engineering AD
- Overgas Inc. AD
- Overgas Iztok AD
- Overgas Metrology AD
- Overgas Mrezhi AD
- Overgas Sever EAD
- Overgas Technika AD
- Overgas Yug AD
- Pravecgas 1 AD
- Remix Bulgaria Ltd.
- Sevlievogas - 2000 AD
- Sustainable Energy Supply Ltd.
- Tassy Ltd.
- Technical University of Sofia
- University of architecture, civil engineering and geodesy
- Vitosha gas Ltd.
- Aleksandar Katancevic
- Aleskandar Aleksandrov
- Angel Dimitrov
- Assoc. prof. dr Todor Trifonov
- Assoc. prof. Efrosima Zaneva-Dobranova
- Assoc. Prof. Georgi Nikolov
- Captain Branimir Trifonov
- CERB - Center for control of metals Ltd.
- CNG Ecogas AD
- Dimcho Syarov
- Emil Tsanov
- Eng. Marin Marinov
- Galco AD
- Gas-energy company - Elin Pelin Ltd.
- Gasstroymontaj AD
- Gastec BG AD
- Georgi Jaigarov
- Homegas Ltd.
- HTI Bulgaria
- Infrastroeji Ltd.
- Kameno Gas Ltd.
- Krum Hristov
- Luben Karatotev
- Lubomir Denchev
- Lubtcho Rusev
- Luchezar Georgiev
- Malin Ezekiev
- Mario Karadjov
- Martin Bojadzhiev
- Milen Kehayov
- Miloslav Katsarov
- Nayden Petkov
- Nikolai Zanev
- Nikolay Pavlov
- Outdoor Trading Ltd.
- Overgas Direct Ltd.
- Overgas Zapad AD
- Penko Efremov
- Petar Tsibranski
- Plastec Ltd.
- Prof. Vasil Balinov
- Rosen Zagorov
- Rusi Slavov
- Slav Nikolov
- Svetoslav Ivanov
- Svilengrad-gaz AD
- The University of Mining and Geology “St. Ivan Rilski”
- Tobogas Ltd.
- Toplomax Ltd.
- Vestitel BG AD
- „AQUASTAR-SYS" OOD