Public domain photograph of laboratory, scientist, free to use, no copyright restrictions image - Picryl description
Public domain photograph - Austro-Hungarian army during World War One, free to use, no copyright restrictions image - Picryl description
Ölfass-Ständer, Luftwäscher, Luftwärmer, Stellage mit Sprengmaterial, Kalkreiniger, Emulsionsreiniger und Ölreiniger.