File:Roundel of Bulgaria (1941–1944).svg - Wikipedia
Bulgarian Air Force History (one of the oldest air forces in Europe) - YouTube
Bulgarian Air Force PZL-43, a Polish built light bomber/reconnaissance aircraft. Bulgarians nicknamed it Chaika (Seagull). This is a pre-WW2 pic judging by the roundel. : r/WWIIplanes
The Bulgarian Air Force in WWII - Kagero via Casemate UK - Reference material - Britmodeller.com
History of the Bulgarian Air Force. Part of 3. Postwar period and modernity
Tu-2 in Bulgaria
Royal Bulgarian Air Force WWII Uniforms Main Page
Messerschmitt Bf 109 E-4 "Arrow" Bulgarian Numbers & Insignia
1 - Bulgaria - Air Force Arado Ar 196 at Plovdiv - Krumovo/Museum of Bulgarian Aviation | Photo ID 311546 | Airplane-Pictures.net
The Bulgarian Air Force in the Second World War - Reference material - Britmodeller.com
Outnumbered and Outgunned, the Bulgarian Air Force Battled the Allies Over Sofia - War Is Boring
Outnumbered and Outgunned, the Bulgarian Air Force Battled the Allies Over Sofia - War Is Boring