sentences:  In "Ba sinh hương lửa", Doan Quoc Sy quoted a Việt Minh officer with the forces surrounding Nà Sản, "The enemy withdrew without our knowledge ... until there was only one battalion left ... the enemy was able to escape and save its entire forces because of our poor military intelligence".The hedgehog tactics earned the French a victory at Nà Sản.As a result, the hedgehog defense became standard practice, and was applied on a larger scale at Điện Biên Phủ.