Bulgarian airplane photos (from 1919-1947)?

Hello all,

I am looking to buy photos (or good quality scan) of Bulgarian airplanes (from 1919-1947).

Best wishes,

Denes

I am looking for precise information on Bulgarian fighters and fighter trainers (including their serial number in the triangle, usually painted on the tail).
I am also looking for good scans of photos showing such aircraft.

Best wishes,

Denes