Can i get this in english. Also please share if you have any data/videos reg. the following types of drilling Hydraulic rotary auger methods: 1 Lead flight kelly bar driven 2. sectional solid stem 3 sectional hollow -stem 4 continous flight solid stem 5 continous flight hollow stem Hydraulic air and water rtary methods: external flush open hole external flush cased dup;ex Pneumatic rotary(top hole hammer) method of drilling 1 external flush open hole