Gaya APA

PETEX., . (1979). Workbook for a primer of oilwell service and workover. (1979). : Texas: Petroleum Extension Service, PETEX ,.

Gaya MLA

PETEX., . "Workbook for a primer of oilwell service and workover.". 1979 : Texas: Petroleum Extension Service, PETEX ,, 1979. Text.