Diamond drilling bits [slaid]/

Eitemau Tebyg

• The bit
  gan: University of Texas. Petroleum Extension Service
  Cyhoeddwyd: (1976)
• The bit /
  gan: Leecraft, Jodie, et al.
  Cyhoeddwyd: (1981)
• Roller-cone bits [slaid]
  Cyhoeddwyd: (1977)
• Rotary, kelly and swivel
  gan: University of Texas. Petroleum Extension Service
  Cyhoeddwyd: (1966)
• An investigation into the percussive drill bit penetration of rock /
  gan: 322463 Mustapha Kamal Shahrom