Gaya APA

Service, P, E. (1971). Lesson in Rotary Drilling. Unit l Lesson 10. Safe Handling Of Hydrogen Sulfide Gas . : Texas : Petroleum Extension Service (PETEX),.

Gaya MLA

Service, Petroleum, Extension. "Lesson in Rotary Drilling. Unit l Lesson 10. Safe Handling Of Hydrogen Sulfide Gas". : Texas : Petroleum Extension Service (PETEX),, 1971. Text.