TY  - BOOK
ED  - Petroleum Extension Service. University of Texas.
TI  - The bit: Revised
T2  - Lessons in rotary drilling
U1  - 622.338.1 U58 0001201 
PY  - 1976///
CY  - Houston, Texas
PB  - Petroleum Extension Service ; International Association of Drilling Contractors, IADC
KW  - Equipos de perforación
KW  - Trépanos
ER  -