This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Unofficial Bulgarian Wartime flag. Unofficial Bulgarian Wartime flag svg Unofficial Bulgarian wartime National and War flag used only during military operations between and In fact it represents reversed Bulgarian National flag According to cite book za gerbovete Chast vtorazname htm Ivan Voynikov History of the Bulgarian State