184,947 views
Learn to create websites and applications in Python at SkillFactory: https://go.skillfactory.ru/dGgYDQ Refund for the course if you do not find a job after training + 45% discount with promo code HISTORY until 07/31/2023 Erid: 2Vtzqw9b9px The underground front is much older than the air, sea and even underwater. But very little is said about it. Sources, links and additional information: The Underground Front of World War I - https://www.amazon.com/Underground-Wa... The Underground Theater of War - https://academic.oup.com/book/12248 The History of Underground Battles - https://www.fpri.org/article/2015/04/... And another article - https://www.hudson.org/national-secur... The Largest Battle of World War I - https://www.bbc.com/news/magazine-136... The Battle of Fukua - https://woostergeologists.scotblogs.w... Music in the video - Two Places by A Himitsu / a-himitsu Music by A Himitsu (https://youtube.com/channel/UCgFwu-j5...) Free Download / Stream: http://bit.ly/TwoPlaces-A-Himitsu Music promoted by Audio Library • Two Places – A Himitsu (No Copyright ...