Secret Tunnel WarfareDVD - 2016
During World War I, the Allies and Germans repeatedly struggled to break the hideous stalemate of trench warfare. In the winter of 1916, Allied engineers devised a massive surprise attack on the German army. Nova follows bomb disposal experts as they clear topsoil packed with shrapnel and unexploded shells and probe one tunnel system connected to what is probably the world's largest unexploded bomb.
Publisher: [United States] : PBS Distribution, 
Branch Call Number: DVD-ED 940.4144 SECRET
Characteristics: video file,DVD video digital,optical,stereo 1 videodisc (60 min.) : sound, color ; 4 3/4 in.
Alternative Title: Nova (Television program). Secret tunnel warfare.