APA
American Petroleum Institute A., . (2015). Specification for subsurface safety valve equipment. Washington: American Petroleum Institute, API.
Chicago
American Petroleum Institute API, . 2015. Specification for subsurface safety valve equipment. Washington: American Petroleum Institute, API.
Harvard
American Petroleum Institute A., . (2015). Specification for subsurface safety valve equipment. Washington: American Petroleum Institute, API.
MLA
American Petroleum Institute API, . Specification for subsurface safety valve equipment. Washington: American Petroleum Institute, API. 2015.