vibro тэжээгч нунтаг 2 кг цаг
Далан — Википедиа нэвтэрхий толь "Well Diggers Trick", June 1951, Popular Science article on how flood control engineers were using an old method to protect flood levees along rivers from seepage undermining the levvee - i.e. drawings and illustrations "Design and Construction of Levees" US Army Engineer Manual EM-13, 30 April 2000, about the design and ...