Stereoview of Serbian Soldiers in a Trench Probably on the Macedonian Front Titled "Serbian Trench - Awaiting Phone Call From Listening Post to Fire Rocket For Illuminating 'No Man's Land.'" (1910's)

Stereoview of Serbian soldiers in a trench probably on the Macedonian Front titled "Serbian trench - awaiting phone call from listening post to fire rocket for illuminating 'No man's land.'" Published by the Keystone View Company.

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A Serbian Soldier Loading a Mortar in a Trench Somewhere on the Macedonian Front During World War 1 (1910's)

A Serbian soldier loading a mortar in a trench somewhere on the Macedonian Front during World War 1. Published by Keystone View Company.

Source.

View of a Line of Serbian Cavalry Somewhere in the Balkans During World War 1

View of a line of Serbian cavalry somewhere in the Balkans during World War 1.

Source.