An Elaborate process of tunnels dug inside the mountainsides enabled the Viet Minh to safeguard its artillery pieces by constantly moving them to circumvent discovery. A number of hundred kilometers of trenches permitted the attackers to move progressively nearer into the French encampment. \ Pinney et al. (2008) concluded that https://www.kanzlei-trachtenberg.at/group/mysite-231-group/discussion/01b57b83-8798-4ca4-831e-c0c3f3d5124d