Gaya APA

Services., P, E., Cont, A, A, O, O, D. (1980). Lessons in rotary drilling. unit I lesson 1. the rotary rig and its components. (1980). : Texas : Petroleum Extension Service,.

Gaya MLA

Services., Petroleum, Extension., Cont, Ame., Ass., Of, Oilwell, Dril. "Lessons in rotary drilling. unit I lesson 1. the rotary rig and its components.". 1980 : Texas : Petroleum Extension Service,, 1980. Text.