Gaya APA

Service., P, E. (1971). Lessons in well servicing and workover lesson 4 : well completion methods. (1971). : Texas : Petroleum Extension Service,.

Gaya MLA

Service., Petroleum, Extension. "Lessons in well servicing and workover lesson 4 : well completion methods.". 1971 : Texas : Petroleum Extension Service,, 1971. Text.