APA

American Petroleum Institute A., . (2007). Metal plug valves -Flanged, threaded and welding ends. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 2007. Metal plug valves -Flanged, threaded and welding ends. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (2007). Metal plug valves -Flanged, threaded and welding ends. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Metal plug valves -Flanged, threaded and welding ends. Washington: American Petroleum Institute, API. 2007.