Cita APA (7th ed.)
(2018). Science & Research. Union of Scientists - Stara Zagora.
Cita Chicago (17th ed.)
Science & Research. Union of Scientists - Stara Zagora, 2018.
Cita MLA (9th ed.)
Science & Research. Union of Scientists - Stara Zagora, 2018.
Atenció: Aquestes cites poden no estar 100% correctes.